THE 

f MOf lOAL  IIOIMIIO 


COMPEISING 


A  CLEAR  EXPOSITION 


OF  THE 


PRINCIPLES  AND  PRACTICE  OF  MECHANISM. 


WITH   THEIK  APPLICATION   TO 


THE  INDUSTRIAL  ARTS. 


By  J.  A.  DRAKE. 


PHILADELPHIA,  PA.: 

J.    W.    LU  K  ENB  AC  H  ,  Publisher. 

Price  $2.50.    Bound  in  Cloth. 

1887 


Entered,  according  to  Act  of  Congress,  in  the  year  1879,  by 

J.  W.  LUKENBACH, 
in  the  Office  of  the  Librarian  of  Congress,  at  Washington. 


PREFACE. 


■jlTANY  mechanical  books  arc  obscured  by  theo- 
retical problems  and  complicated  mathematical 
formulae,  a  defect  which,  it  is  believed,  has  been 
obviated  in  this  volume,  I  trust  my  efforts  will  be 
duly  appreciated  by  every  "  Practical  Mechanic." 

THE  AUTHOR. 


Definition  of  Arithmetical  Signs  used  in  the  Work. 

=  When  we  wish  to  state  that  one  quantity  or  number  is  equal 
to  another  quantity  or  number,  the  sign  of  equaiity  =  is  em- 
ployed.    Thus  3  added  to  2  =  5,  or  3  added  to  2  is  equal  to  5. 

4-  When  the  sum  of  two  quantities  or  numbers  is  to  be  taken, 
the  sign  plus -{- is  placed^  between  them.  Thus  3  +  2  =  5;  that 
is,  the  sum  of  3  and  2  is  5.     This  is  the  sign  of  Addition. 

—  When  the  difference  of  two  numbers  or  quantities  is  to  be 
taken,  the  sign  minus  —  is  used,  and  shows  that  the  latter  num- 
ber or  quantity  is  to  be  taken  from  the  former.  Thus  5  —  2  =  3. 
This  is  the  sign  of  Subtraction. 

X  When  the  product  of  any  two  numbers  or  quantities  is  to  be 
taken,  the  sign  into  X  is  placed  between  them.  Thus  3x2  =  6. 
This  is  the  sign  of  Multiplication. 

-T-  When  we  are  to  take  the  quotient  of  two  quantities,  the  sign 
by  -7-  is  placed  between  them,  and  shows  that  the  former  is  to  be 
divided  by  the  latter.  Thus  6-^2  =  3.  This  is  the  sign  of 
Division.  But  in  some  cases  in  this  work,  the  mode  of  division 
has  been  to  place  the  dividend  above  a  horizontal  line,  and  the 
divisor  below  it,  in  the  form  of  a  vulgar  fraction,  thus: 

Dividend       rv     *•     *  ^      o 

T^.  ■ =  Quotient.  x  =  3. 

Divisor  2 

When  the  square  of  any  number  or  quantity  is  to  be  taken,  this 
is  denoted  by  placing  a  small  figure  2  above  it  to  the  right.  Thus 
6-  shows  that  the  square  of  G  is  to  be  taken,  and  therefore  6-  ^=  6 
X  6  =  36. 

When  we  wish  to  show  that  the  square  root  of  any  number  or 
quantity  is  to  be  taken,  this  is  denoted  by  i)lacing  the  radical  sign 
v/  before  it.  Thus  /  36  shows  that  the  square  root  of  36  ought 
to  be  taken,  hence   y  36  =  6. 

The  common  marks  of  proportion  are  also  used,  viz.,  :  :  :  :  as 
3  :  6  :  :  4  :  8,  being  read  3  is  to  6  as  4  is  to  8 

The  application  of  these  signs  to  the  expression  of  rules  is  ex- 
ceedingly simple.  Thus,  connected  with  the  circle  we  have  the 
following  rules: 

1st.  The  circumference  of  a  circle  will  be  found  by  multiplying 
the  diameter  by  3.1416. 

2d.  The  diameter  of  a  circle  may  be  found  by  dividing  the  cir- 
cumference by  3.1416. 

3d  The  area  of  a  circle  may  be  found  by  multiplying  the  half  of 
the  diameter  by  the  half  of  the  circumference,  or  by  inulti])lyiiig 
together  the  diameter  and  circumference,  and  dividing  the  pro- 
duct by  4,  or  by  scjuaring  the  diameter  and  multiplying  by  .7854. 

Now  all  these  rules  may  be  thus  expressed : 

Ist.  diameter  X  3. 1416  =  circumference 

n^  circuinff'rence 

^^  rTTTTT =  diameter. 

3  1110 


3d. 


diameter      circumference 

2-X 2 =  ""*• 

diameter  X  circumference 

or,  . =area. 

4 

or,  diameter"  X  •  7854  =  area. 


THE  PEACTICAL  MECHANIC. 


A    TABLE 


CONTAXNTNG   THE 


DIAMETEES,  CIECUMFERENCES,  AND  AEEAS 
OF  CIRCLES, 


AXD    THE 


CONTENTS  OF  EACH  IN  GALLONS  AT  1  FOOT  IN  DEPTH 


UTILITY   OF   THE   TABLE. 

EXAMPLES. 

1.  Eeqtiired  the  circumference  of  a  circle,  the  diameter  being 
five  inches  ? 

In  the  column  of  circumferences,  opposite  the  given  diameter, 
stands  15. 708  inches,  the  circumference  required. 

2.  Kequired  the  capacity,  in  gallons,  of  a  can,  the  diameter 
being  6  feet  and  depth  10  feet? 

In  the  fourth  column  from  the  given  diameter  stands  211.4472, 
being  the  contents  of /i  can  6  feet  in  diameter  and  1  foot  in  depth, 
■which  being  multiplied  by  ten  gives  the  required  contents,  two 
thousand  one  hundred  fourteen  and  a  half  gallons. 

3.  Any  of  the  areas  in  feet  multiplied  by  .03704,  the  product 
equals  the  number  of  cubic  yards  at  1  foot  in  depth. 

4.  The  area  of  a  circle  in  inches  multiplied  by  the  length  or 
thickness  in  inches,  and  by  .263,  the  product  equals  the  weight  in 
pounds  of  cast  iron. 


6        DIAMETERS  AND  CIRCUMFEREXCES  OF  CIRCLES. 

Diameters  and  Circumferences  of  Circles,  and  the 
Contents  in  Gallons  at  1  Foot  in  Depth. 

Area  in  laches. 


Diam. 

Circ.  iu.| 

Area  in. 

Gallons.  | 

Diam. 

Circ.  in. 

Area  in.  1 

Gallons. 

1  ia. 

3.U1G' 

.7834 

.04034 

6  \ 

20.420 

33.183 

1.72552 

J. 

3.5343 

.9940 

.05169 

1 

20.813 

34.471 

1.79219 

3.9270 

1.2271 

.06380 

s 

21.205 

35.784 

1.86077 

4 

.1 

4.3197] 

1.4848 

.07717 

21.598 

37.122 

1.93034 

5 

4.7124 

1.7671 

.09188 

7  in. 

21.991 

38.484 

2.00117 

1 

5  1051 

2.0739 

.10784 

i 

22.383 

39.871 

2.07329 

i 

5.4978 

2.4052 

.12506 

i 

22.776 

41.282 

2.14666 

5.8905 

2.7G11 

.14357 

1 

23.169 

42.718 

2.22134 

2  in. 

G2832 

3.1416 

.16333 

J 

23.5G2 

44.178 

2.29726 

6.6759 

3.5465 

.18439 

r,. 

23.954 

4.5. 663 

2.37448 

7.0686 

3.&7G0 

.20675 

24.347 

47.173 

2  45299 

4 

7.4613 

4.4302 

.23036 

24.740 

48.707 

2.53276 

8 

7.8540 

4.9087 

.25522 

8  in. 

25.132 

50.205 

2.61378 

8.24G7 

5.4119 

.28142 

J 

25.515 

51.848 

2.69609 

a 

8.6394 

5.9395 

.30883 

O 

25.918 

53.4.56 

2.77971 

1 

9.0321 

6.4918 

.33753 

26.310 

55.088 

2.86458 

3  in. 

9.424S 

7.0G86 

.36754 

^ 

26.703 

56.745 

2.95074 

i  ■ 

9.8175 

7.6699 

.39879 

£ 

27.096 

58.426 

3.03815 

10.210 

8.2957 

.43134 

1 

27.489 

60.132 

3.12686 

10.602 

8.9462 

.46519 

27.881 

61.862 

3.21682 

;  • 

10.995 

9.6211 

.50029 

9ui. 

28.274 

G3.617 

3.30808 

11.388 

10.320 

•53664 

1 

2S.667 

65.396 

3  40059 

»  . 

11.781 

11.044 

.57429 

1 

29.059 

67.200 

3.49440 

; , 

12.173 

11.793 

.61324 

29.452 

69.029 

3.58951 

r 
4  in. 

12.566 

12.566 

.65343 

1 

29.845 

70.882 

3.08586 

i 

12.959 

13.364 

.69493 

1 

30.237 

72.759 

3.78317 

13.351 

14.186 

.73767 

1 

30.630 

74.662 

3.88242 

13.744 

15.033 

.78172 

31.023 

76.588 

3.98258 

14.137 

15.904 

.82701 

10  in. 

31.416 

78.540 

4.08408 

14.529 

16.800 

.87360 

J 

31.808 

80.515 

4.18678 

5  in. 

14.922 

17.720 

.92144 

1 

32.201 

82.516 

4.29083 

15.315 

18.GG5 

.97058 

32.594 

84  540 

4.  .39608 

15.708 

19.635 

1.02102 

1 

32.9S6 

86.590 

4.50268 

■ 

16.100 

20.629 

1.07271 

1 

33.379 

88.664 

4.61053 

16.493 

21.647 

1.12564 

i 

33.772 

90.7G2 

4.71962 

16.886 

22.690 

1.17988 

1 

34.164 

92.885 

4.82816 

• 

17.278 

23.758 

1.23512 

11  in. 

34.557 

95.033 

4.94172 

17.671 

24.850 

1.29220 

34.950 

97.205 

5.054G6 

1 

18.0t;4 

25.967 

1.35028 

35.343 

99.402 

5.16800 

f 

18.457 

27.108 

1.40962 

35.735 

101.623 

5.28139 

0  in. 

18.819 

28.274 

1.47025 

36.128 

103.869 

5.40119 

19.242 

29.464 

1.53213 

■ 

I 

36.521 

106.139 

5.51923 

I 

10.635 

30.679 

1.59531 

-.{ 

36.913 

103.434 

5.03857 

1 

2  ).027 

31.919 

1.65979 

i 

\ 

37.30G 

110.753 

5.75916 

DIAMETERS  AND  CIRCUMFEREXCES  OF  CIRCLES. 


[Area  in  Feet.  ] 


Diam.   Circ. 

Area  in  ft. 

Gallons.  1  Diam. 

Circ.  1 

Are  I  in  ft. 

Gallons. 

Ft.  In.  Ft 

In. 

1  ft.  depth,  ft.  In. 

Ft. 

In. 

1  ft.  depth. 

3 

1| 

.7854 

5.8735 

4 

10 

15 

n 

18.3476 

137.2105 

1   1 

3 

n 

.9217 

6.8928! 

4 

11 

15 

H 

18.9858 

142.0582 

1   2 

3 

8 

1.0690 

7.9944' 

1   3 

3 

11 

1.2271 

9.1766 

5 

15 

^ 

19.6350 

146.8384 

1   4 

4 

n 

1.3962 

10.4413 

5 

1 

15 

111 

20.2917 

151.7718 

1   5 

4 

5| 

1.5761 

11.7866 

5 

2 

16 

2| 

20.9656 

156.7891 

1   6 

4 

8.^ 

1.7671 

13.2150 

5 

3 

16 

5| 

21.6475 

161.8886 

1   7 

4 

1^ 

1.9689 

14.7241 

5 

4 

16 

9 

22.34' 0 

167  0674 

1   8 

5 

n 

2.1816 

16.3148 

5 

5 

17 

01 

23.0137 

172.3300 

1   9 

5 

5} 

2.4052 

17.9870 

5 

6 

17 

H 

23.7583 

177.6740 

1  10 

5 

9 

2.6398 

19.7414 

5 

7 

17 

4 

24.4835 

183  0973 

1  11 

6 

n 

2.8852 

21.4830: 

5 

8 

17 

n 

25.2199 

188.6045 

5 

9 

18 

0| 

25.9672 

194.1930 

2 

6 

H 

3.1416 

23.4940 

5  10' 

18 

4 

26.7251 

199.8610 

2   1 

6 

H 

3.4087 

25.4916 

5 

11 

18 

''k 

27.4943 

2U5  6133 

2   2 

6 

9i 

3.6869 

27.5720| 

2   3 

7 

o« 

3.9760 

29.7340 

6 

18 

10^ 

28.2744 

211.4472 

2   4 

7 

3^ 

4.2760 

32.6976 

6 

3 

19 

7 

30.6796 

229.4342 

2   5 

7 

7 

4.5869 

34.3027 

6 

6 

20 

4 

33.1831 

248.1564 

2   6 

7 

101- 

4.9087 

36.7092! 

6 

9 

21 

4 

35.7847 

267.6122 

2   7 

8 

n 

5.2413 

39.1964 

o 

2   8 

8 

M 

5.5850 

41.7668' 

7 

21 

111 

38.4846 

287.8032 

2   9 

8 

n 

5.9395 

44.4179 

7 

3 

22 

9? 

41.2825 

308.7270 

2  10 

8 

lOi 

6.3049 

47.1505 

7 

6 

23 

4 

44.1787 

330.3859 

2  11 

9 

U 

6.6813 

49.9654J 

7 

9 

24 

4 

47.1730 

352.7665 

3 

9 

5 

7.0686 

52.8618 

8 

25 

H 

50.2656 

375.9062 

3   1 

9 

81 

7.4666 

55.8382  i  8 

3 

25 

11 

53.4562 

399.7668 

3   2 

9 

m 

7.8757 

58 -8976'!  8 

6 

26 

81 

56.7451 

424.3625 

3   3 

10 

'^ 

8.2957 

62.0386 

S 

9 

27 

4 

60.1321 

449.2118 

3   4 

10 

5§ 

8.7265 

65.2602 

1 

3   5 

10 

8| 

9.1683 

68.5193 

9 

28 

31- 

63.6174 

475.7563 

3   6 

10 

Hi 

9.6211 

73.1504 

9 

3 

29 

o| 

67.2007 

502.5536 

3   7 

11 

3 

10.0846 

75.4166 

9 

6 

29 

104 

70.8823 

530.0861 

3   8 

11 

6^ 

10.5591 

78.9652 

9 

9 

30 

7i 

74.6620 

558.3522 

3   9 

11 

^i 

11.0446 

82.5959 

it 

3  10 

12 

5.t 

11.5409 

86.3074  10 

31 

5 

78.5400 

587.3534 

3  11 

12 

3i 

12.0481 

90.10J4  10 

3 

32 

21 

82.5160 

617.0876 

10 

6 

32 

Hi' 

86.5903 

647.5568 

4 

12 

6| 

12.5664 

93.9754  :10 

9 

33 

91 

90.7627 

678.2797 

4   1 

12 

n 

13.0952 

97.931011 

34 

61 

95.0334'  710.6977 

4   2 

13 

1 

13.635:J 

101.9701  it; 

3 

35 

8 

U 

99.4021 

743.3686 

4   3 

13 

n 

14.1862 

103.0300' 

111 

6 

36 

103.8691 

776.7746 

4   4 

13 

n 

14  7479 

110.2907 

11 

9 

36 

2 

lOi 

108.4342 

810.9143 

4   5 

13 

IOa 

15.3206 

114.5735 

j.-^  8 

4   6 

14 

15.9043 

118.9386, |12 

37 

8| 

113.0976 

848.1890 

4   7 

14 

16.4986 

123.3830  12 

3 

J8 

5t 

117.8590 

881.3966 

4   8 

14 

7i 

17.104^ 

127.9112  12 

6 

39 

3| 

122.7187 

917.7395 

4   9 

14 

11 

17.7215 

132.5209' 12 

9 

10 

Of 

127.6765 

954  8159 

DIAMETERS  AND  CIRCUMrERE2>'CES  OF  CIRCLES. 


Diameters  and  Circumferences  of  Circles,  and  the 
Contents  in  Gallons  at  1  Foot  in  'Depth.— {Cont'd.) 

[Area  in  Fevt.l 


Ciam. 

Circ. 

Area  iu  ft 

Gallons. 

Diani.   Circ. 

Area  ill  ft. 

Gallons. 

Ft.  la. 

Ft. 

In. 

1  ft.  depth. 

Ft.  In 

Ft. 

In. 

1  ft.  depth. 

13 

4'J 

10 

132.732G 

992.6J74 

22 

69 

If 

380.1336 

2842.7910 

13  3 

41 

7^ 

137.88G7, 

1031.1719 

22 

3  69 

lOi^ 

388.8220 

2907.7664 

13  6 

t2 

^ 

143.1391 

10711.4514 

22 

670 

8i 

397.6087 

2973.4889 

13  9 

43 

2i 

U.S.  4896 

1108.0645 

22 

9  71 

5s 

406.4935 

3039.9209 

11 

43 

llj 

153  9384 

1151.2129 

23 

72 

3 

415.4766 

3107.1001 

14  3 

44 

n 

159.48.32 

1192.6940 

23 

3 

73 

OJ 

424.5577 

3175.0122 

14  G 

45 

H 

165.1303 

1234.9104 

23 

6  73 

91 

433.7371  3243.6595 

14  9 

16 

4 

170,8735 

1277.8615 

23 

9  74 

71 

443.0146 

3313.0403 

15 

47 

li 

176.7150 

1321.5454 

24 

75 

n 

452.3904 

3383.1563 

15  3 

17 

104 

182.6545 

1365.9634 

24 

3 

76 

4 

461.8642 

3454.0051 

15  G 

4S 

H 

188.G923 

1407.5165 

24 

6 

76 

111 

471.4363 

3525.5929 

15  9 

49 

5;i 

194.8282 

1457.0032 

21 

9 

77 

9 

481.1005 

3597. 90G8 

16 

50 

3J 

201.0624 

1503.6250 

25 

78 

Gl 

490.8750 

3670.9596 

IG  3 

51 

0.1 

207.3916 

1550.9797 

25 

3|79 

31 

5')0.7415 

3744.7452 

IG  G 

51 

10" 

213.8251 

1.')9'.).0696 

25 

6'80 

i; 

510.7063 

3819.2657 

IG  9 

52 

7'' 

'8 

220.3537 

1647,8930 

25 

9 

80 

lOil  520.7692 

3894.5203 

17 

53 

4^ 

226.9806 

1697.4516 

26 

81 

8  J  530.9304 

3970.5098 

17  3 

54 

n 

233.7055 

1747.7431 

26 

3 

82 

51  541.1896 

4047.2322 

17  G 

54 

111 

240.5287 

179S.7698 

26 

61,83 

3  1551.5471 

4 124.6898 

17  9 

55 

247.4500 

1850.5301 

26 

9|84 

02  562.0027 

"1 

4202.9610 

18 

5G 

^ 

2r,4.4696 

1903.0254 

27 

84 

9;  .572.5566 

4281.8072 

18  3 

57 

4 

261.. 5872 

19.56.2537 

27 

3!85 

8i  583. 2085,4361.4664 

18  6' 58 

13 

268.8031 

2010.2171 

27 

686 

4|  593. 9.58714441. 8G07 

18  9  53 

io| 

276.1171 

2061.9140 

27 

9!87 

2i  604.8070  4522.9886 

1 

19   59 

^ 

28.3.5294 

2120.3462 

28 

S7 

lU  615.7536  4604.8517 

19  3  GO 

n 

291  0397 

2176.5113 

28 

3  88 

9'  620.7982 

46K6.4S76 

19  6GI 

29S,64S3 

2233.2914 

28 

6  89 

62  637.9411 
3^649.1821 

4770.7787 

19  9C2 

Oi 

306  3550 

2291.0152 

28 

9  99 

4854.8434 

20   G2 

9J 

3  U.  1600 

2349.4141 

29 

91 

11  G60.52H 
10  671.9587 

4939. G432 

20  3G3 

\ 

322.06  51) 

210s.  5 1.59 

29 

3  91 

502.5.1759 

20  G  G4 

2 

3:j().0(;i3 

2168.3.528 

29 

(;  92 

8|  (;83.4943 

5111.4487 

21)  9  G5 

1 

338.1637 

2528.9233 

29 

9  93 

5^695.1280 

5198.4451 

21 

65 

lie 

.346.3614 

2590.2290 

30 

94 

2  J  706.8600 

528G.1818 

21  3!G6 

9 

351.6571 

2652.  2.532 

30 

3  95 

03  7 18.  ('.900 

.5374.6512 

21  CG7 

i\ 

.363.0511 

27150413 

30 

C:9.) 

9{  730.6183 

5463.85.58 

21  9G8 

371.5132  2778.  .5486 

30 

9!9G 

7(742  6447  55,53.7940 

CONTENTS  OP  FEUSTUM  OF  A  CONE.       9 

Contents  in  Gallons  of  the  Frustum  of  a  Cone. 

To  find  the  Contents  in  Gallons  of  a  Vessel  whose  diameter  is 
larger  at  one  end  than  the  other,  such  as  a  Bowl,  Pail,  Firkin, 
Tub,  Coflfee-pot,  &c. 

Rule.  — Multiply  the  larger  diameter  by  the  smaller,  and  to  the 
product  add  one-third  of  the  square  of  their  difference,  multiply 
by  the  height,  and  multiply  that  product  by  .0034  for  Wine  Gal- 
lons and  by  .002785  for  Beer. 

Example.  —Required  the  contents  of  a  Coffee-pot  6  inches  di- 
ameter at  the  top,  9  inches  at  the  bottom,  and  18  inches  high. 


Large  diameter  9 
Small      do.  6 

54 
^  of  the  square    3 

57 
height    18 

456 
57 


Brought  up     1026 
.0034 


4104 
3078 


3.4884  AVine  Gallons, 
or  nearly  3i  gallons. 


Carried  up     1026 

1026  multiplied  by  .002785  equal  2.8574  JJter  Gallons. 


Kule  to  find  the  Contents  in  Gallons  of  any  Square 

Vessel. 

Rule. — Take  the  dimensions  in  inches  and  decimal  parts  of  an 
inch,  multiply  the  length,  breadth,  and  height  together,  and  then 
multiply  the  product  by  .004329  for  Wine  Gallons,  and  by  .003546 
for  Ale  Gallons. 

Example. — How  many  Wine  Gallons  will  a  box  contain  that  is 
10  feet  long,  5  feet  wide,  and  4  feet  deep  ? 

Length  in  inches. 
Breadth  in     do. 


Height  in  inches, 


120 
60 

Brought  up  345600 
.004329 

7200 
48 

3110400 
691200 
1036800 
1382400 

57600 
28800 

1496.102400  gallons, 
or  1496  galls,  and  3^  gills. 

345600 

10     CONTENTS  IN  GALLONS  OF  CYLINDRICA],  VESSELS. 

Contents  in  Gallons  of  Cylindrical  Vessels. 

Rule. — Take  the  dimensions  in  inches  and  decimal  jiartsof  an 
inch.  Square  the  diameter,  miiltiply  it  by  the  length  in  inches, 
and  then  multiply  the  product  by  .0034  for  Wine  Gallons,  or  by 
.002785  for  Ale  Gallons. 

Example.  — How  many  U.  S.  Gallons  will  a  Cylindrical  Vessel 
contain,  whose  diameter  is  9  inches  and  length  9^  inches? 
Diameter,  9  Brought  up     769.5 

9  .0034 


Square  Diam.    Si 
Length,             9.5 

30780 
23085 

405 
729 

2.G1630 
or  2  gallons  and  5  pints 

Carried  up 

7G9.5 

To  ascertain  the  Weights  of  Pipes  of  Various 
Metals,  and  any  Diameter  required. 


Thickness  iu 

l«arts  of  nil 

Wrought  Iron. 

Copper. 

Lead. 

inch. 

1-32 

.320 

lU  lbs.  plate     .38 

2  1bH 

.  lead    .483 

1-lG 

.053 

23  i         "            -.70 

4 

.9G7 

3-32 

.97G 

35'         "           1.14 

^ 

1.45 

1-8 

1.3 

iCk         "          1.52 

8 

1.933 

5-32 

1.G27 

58           "          1  9 

9.V 

2.417 

3-1 G 

1.95 

70          "          2.28 

11 

2.9 

7-32 

2.277 

80  J         "          2.GG 

13 

3.383 

1-4 

2.6 

93           "          3.04 

15 

3.8G7 

Rule. — To  the  interior  diameter  of  tho  pipe,  in  inches,  add  the 
tliicknesH  of  the  metal;  multiply  the  sum  by  the  decimal  num- 
bers opposite  the  re(piired  tliieloiesH  and  under  the  metal's  name; 
also  by  the  length  of  tho  pipe  in  feet,  and  tho  product  is  the 
wiight  of  tho  jiipo  in  lbs. 

1.  Rcrpiired  tho  weiglit  of  a  cojijxt  iiipo  whoso  interior  diam- 
eter is  7.^  inches,  its  length  (>]  foet,  and  the  metal  j^  of  an  inch  in 
thickness. 

7.5  -(-  .121  -^  7.G25  X  152  X  G.25  =  72.4  lbs. 

2.  What  is  tho  weight  of  a  lead(!n  i)ipo  IH.l  feet  in  length,  3 
inches  interior  diameter,  and  the  metal  ',  of  an  inch  in  thickness? 

3  -f  .25  ^  3.25  X  3.8G7  X  1H.5  =  232.5  lbs. 


WEIGHT  OF  WATER  AND  DECIMAL  EQUIVALENTS.     11 

Weight  of  Water. 

1  Cubic  inch equal  to  .03G17  pound. 

12  Cubic  inches equ.nl  to  .431  pound. 

1  Cubic  foot equal  to      G2.5  pounds. 

1  Cubic  foot equal  to        7.50  U.  S.  gallons. 

■1.8  Cubic  feet equal  to    112.00  povmds. 

35.84  Cubic  feet equal  to  2240.00  pounds. 

1  Cylindrical  inch equal  to  .02842  pound. 

12  Cylindrical  inches equal  to  .  341  pound. 

1  Cylindrical  foot equal  to      49.10  pounds. 

1  Cylindrical  foot equal  to        G.OO  U.  S.  gallons. 

2.282  Cylindrical  feet ...equal  to    112.00  pounds. 

45.64  Cylindrical  feet equal  to  2240.00  poimds. 

11.2  Imperial  gallons equal  to    1 12.00  pounds. 

224  Imperial  gallons equal  to  2240.00  pounds. 

13.44  United  States  galls equal  to    112.00  pounds. 

268.8  United  States  galls equal  to  2240.00  pounds. 

Centre  of  pressure  is  at  two-thirds  depth  from  surface. 


Decimal  Equivalents  to  the  Fractional  Parts  of  a 
Gallon,  or  an  Inch. 

{The  Inch,  or  Gallon,  being  divided  into  32  pa?'/s.] 
[In  multiplying  decimals  it  is  usual  to  drop  all  but  the  first  two  or  three  figures  J 


. 

Gallon. 

1 

Gallon, 

w 

Gallon. 

m 

Deci- 

or 

3 

00   ' 

Deci- 

or 

m 

Deci- 

or 

:S 

n 

aa 

mals. 

Inch 

1 

s 
1 

1 

mals. 

Inch. 
3-8 

12 

3 

mals. 

Inch. 

O 
23 

54 

O" 

.03125 

1-32 

.375 

.71875 

23-32 

2J 

.0G25 

1-16 

2 

1 

4 

.4062") 

13-32 

13 

3i 

1^ 

.75 

3-4 

24 

6 

3 

.09375 

3-32 

3 

1 

? 

4375 

7-16 

14 

U 

11 

.78125 

25-32 

25 

64 

34 

.125 

1-8 

4 

1 

4 

46875 

15-32 

15 

3i 

n 

.8125 

13-16 

26 

dk 

34 

.15625 

5-32 

5 

u 

i 

.5 

1-2 

16 

4 

2 

.84375 

27-32 

27 

H 

Si 

.1875 

3-16 

6 

u 

1 

.53125 

17-32 

17 

H 

2f 

.875 

7-8 

28 

7 

3S 

.21875 

7-32 

7 

H 

7 

s 

.5625 

9-16 

18 

M 

24 

.90625 

29-32 

29 

74 

31 

.25 

1-4 

8 

2 

1 

.59375 

19-32 

19 

n 

n 

.9375 

1.5-16 

30 

7.^^ 

.28125 

9-32 

9 

24 

u 

.625 

5-8 

20 

5 

24 

96875 

31-32 

31 

74;3J 

.3125 

5-16 

10 

■u 

l.i 

.65625 

21-32 

21 

54 

2S 

1.000 

1 

32 

8    4 

.31375 

11-32 

11 

n 

li 

.6875 

11-16 

22 

H 

24 

Application.  —Required  the  gallons  in  any  Cylindrical  Vessel. 
Suppose  a  vessel  9.}  inches  dee]5,  9  inches  diameter,  and  contents 
2.6163,  that  is,  2  gallons  and  61  hundredth  parts  of  a  gallon;  now 
to  ascertain  this  decimal  of  a  gallon,  refer  to  the  above  Table  for 
the  decimal  that  is  nearest,  which  is  .625,  opposite  to  which  is 
5-8ths  of  a  gallon,  or  20  gills,  or  5  pints,  or  2  J  quai'ts,  consequently 
the  vessel  contains  2  gallons  and  5  pints. 

Inches. — To  find  what  part  of  an  inch  the  decimal  .708  is. 
Refer  to  the  above  Table  for  the  decimal  that  is  nearest,  which  is 
.71875,  opj)osite  to  which  is  23-32,  or  nearly  3-4ths  of  an  inch. 


12 


TIN   PLATES. 

Tin  Plates. 

Size,  Length,  Breadth,  and  Weight. 


No.  of 

Length  and 

Weiebt 

per 

Bkand  Mars. 

Sheets 
in  Box. 

Breadth. 

] 

Box 

Inches. 

Cwt 

.qv 

lbs. 

1  C 

225 

14  by  10 

1 

0 

0 

" 

1    X 

225 

14  by  10 

1 

1 

0 

1    XX 
1    XXX 

1  xxxx 

225 
225 
225 

14  by  10 
14  by  10 
14  by  10 

1 
1 
1 

1 

2 
3 

21 
14 

7 

Each  1  x  advances 
$1.75  to  $2.00. 

1  xxxxx 

225 

14  by  10 

2 

0 

0 

1  xxxxxx 

225 

14  by  10 

2 

0  21 

, 

D  C 

100 

17  by  VZh 

0 

3 

14 

a3   IK   O  00 

D  X 
D  XX 

lOD 
100 

17  by  121 
17  by  121 

1 
1 

0 

1 

14 

7 

f  siz 
pose 
Q  pr 
re   e 

D  XXX 

100 

17  by  12.i 

1 

2 

0 

D  xxxx 

100 

17  by  121 

1 

2 

21 

D  xxxxx 
D  xxxxxx 

100 
100 

17  bv  I'i.i 
17  by  12i 

1 
2 

3 
0 

14 
7 

.S          CO 

•'  o  oj  is 

S  D  C 

200 

15  by  11 

1 

1 

27 

c:  C^ii  a>  CO 

S  D  X 

200 

15  by  11 

1 

2 

20 

tCgc.|-5 

S  D  XX 

200 

15  by  11 

1 

3 

13 

a     .S  fl-S 
c  -7-  .C  S  P 

S  1>  XXX 

200 

15  by  11 

2 

0 

C 

S  D  XXXX 

200 

15  by  11 

2 

0 

27 

S  1)  xxxxx 
S  D  xxxxxx 

200 
2U0 

15  by  11 
15  by  11 

2     1  20 

2     2  13 

about 

In  add 
impoi 
ually  c 
rtion 
imed  r 

TTT  Taggers, 

225 

14  by  10 

1 

0 

0 

.2sa^ 

1  C 

225 

12  by  12 

1    X 

225 

12  by  12 

1    XX 

225 

12  by  12 

1 

1    XXX 

2?5 

12  by  12 

About  the  same 

1  xxxx 

225 

12  by  12 

. 

weight  ])tr  Box  as 
[■  the     jilates    above 

1  c 

112 

11  by  20 

of  similar   brand, 

1  x 

112 

14  bv  20 

M  by  10. 

1    XX 

112 

1 1  bv  20 

1    XXX 

112 

11  bV  21) 

1    XXXX 

112 

11  by  20 

Letuhd  or  \  1  C 

112 

14  by  20 

1 

0 

0 

[  For  llmfing. 

Tenics     f  1  x 

112 

14  by  20 

1 

1 

0 

MENSURATION. 


13 


Oil  Canisters  {frcm  2.}  to  125  galls.),  with  the  Quantity 
and  Quality  of  Tin  required  for  Custom  Work. 


Galls. 

Quantity  and  Quality. 

Galls. 

Quantity  and  Quality. 

^ 

8 
10 
15 

2    Plates,  I  X  in  body, 

2         "   SDX 

2         "       DX 

4        "       IX 

3^       "       DX 

4         "       DX 

33 

45 

60 

90 

125 

13^  Plates,  IX  in  body,  3 

breadths  high. 
1 3i  Plates,  SDXin  body. 
13^      "         DX       " 
\b\      "         DX       "      * 
20        "         DX       " 

*  The  bottom  tier  of  plates  to  be  placed  lengthwise. 


MENSURATION. 


Of  the  Circle,  Cylinder,  Sphere,  &c. 

1.  The  circle  contains  a  greater  area  than  any  other  plane  figure 
bounded  by  an  equal  perimeter  or  outline. 

2.  The  areas  of  circles  are  to  each  other  as  the  squares  of  their 
diameters. 

3.  The  diameter  of  a  circle  being  1,  its  circumference  equals 
3.1416. 

4  The  diameter  of  a  circle  is  equal  to  .31831  of  its  circumfer- 
ence. 

5.  The  square  of  the  diameter  of  a  circle  being  1,  its  area 
equals  .7854. 

6.  The  square  root  of  the  area  of  a  circle,  multiplied  by  1. 12837, 
equaLs  its  diameter. 

7.  The  diameter  of  a  circle  multiplied  by  .8802,  or  the  circum- 
ference multiplied  by  .2821,  equals  the  side  of  a  square  of  equal 
area. 

8.  The  sum  of  the  squares  of  half  the  chord  and  versed  sine 
divided  by  the  versed  sine,  the  quotient  equals  the  diameter  of 
corresponding  circle. 

9.  The  chord  of  the  whole  arc  of  a  circle  taken  from  eight  times 
the  chord  of  half  the  arc,  one-third  of  the  remainder  equals  the 
length  of  the  arc;  or, 

10.  The  number  of  degrees  contained  in  the  arc  of  a  circle, 
multiplied  by  the  diameter  of  the  circle  and  by  .008727,  the  pro- 
duct equals  the  length  of  the  arc  in  equal  terms  of  unity. 

11.  The  length  of  the  arc  of  a  sector  of  a  circle  multiplied  by 
its  radius,  equals  twice  the  area  of  the  sector. 

12.  The  area  of  the  segment  of  a  circle  equals  the  area  of  the 
sector,  minus  the  area  of  a  triangle  whose  vertex  is  the  centre, 
and  whose  base  equals  the  chord  of  the  segment;  or. 


14  MENSURATION. 

13.  The  area  of  a  segment  may  be  obtainetl  by  dividing  the 
height  of  the  segment  by  the  diameter  of  the  circle,  and  multiply- 
ing the  corresponding  tabular  area  by  the  square  of  the  diameter. 

14.  The  sum  of  the  diameters  of  two  concentric  circles,  miilti- 
plied  by  their  diflerence  and  by  .7854,  equals  the  area  of  the  ring 
or  space  contained  between  them. 

15.  The  sum  of  the  thickness  and  internal  diameter  of  a  cylin- 
dric  ring,  multi])lied  by  the  square  of  its  thickness  and  by  2.4G74, 
equals  its  solidity. 

16.  The  circumference  of  a  cylinder,  multiplied  by  its  length 
or  height,  equals  its  convex  surface. 

17.  The  area  of  the  end  of  a  cylinder,  multiplied  bj'  its  length, 
equals  its  solid  contents. 

18.  The  area  of  the  internal  diameter  of  a  cylinder,  multiplied 
by  its  depth,  ecpials  its  cubical  cajiacity. 

19.  The  square  of  the  diameter  of  a  cylinder,  multiplied  by  its 
length  and  divided  by  any  other  reqiiired  length,  tlie  scpiare  root 
of  the  quotient  equals  the  diameter  of  the  other  cylinder  of  equal 
contents  or  capacity. 

20.  The  square  of  the  diameter  of  a  sphi're,  multiplied  by 
3.1416,  equals  its  convex  surface. 

21.  The  cube  of  the  diameter  of  a  sphere,  multiplied  by  .5236, 
equals  its  solid  contents. 

22.  The  height  of  any  spherical  segment  or  zone,  multiplied 
by  the  diameter  of  the  sphere  of  which  it  is  a  part,  and  by  3.1416, 
equals  the  area  or  convtx  surface  of  the  segment;  or, 

23.  The  height  of  the  segment,  multiplii.'d  by  the  circumfer- 
ence of  the  sphere  of  which  it  is  a  part,  equals  the  area. 

24.  The  solidity  of  any  spherical  segment  is  equal  to  three 
times  the  square  of  the  radius  c>f  its  base,  plus  the  sqxiare  of  its 
height,  and  multiplied  by  its  height  and  by  .5236. 

25.  The  solidity  of  a  spherical  zone  e<iuals  the  sum  of  the 
squares  of  the  radii  of  its  two  ends,  and  one-third  the  square  of 
its  height,  multiplied  by  the  height,  and  by  1.5708. 

26.  The  capacity  of  a'cylinder,  1  foot  in  diameter  and  1  foot  in 
length,  ecjiials  5. 875  of  a  United  States  gallon. 

27.  The  capacity  of  a  cylinder,  1  inch  in  diameter  and  1  foot  in 
length,  equals  .()iu8  of  a  United  States  gallon. 

28.  The  capacity  of  a  cylimler,  1  inch  in  diameter  and  1  inch 
in  length,  e(]uals  !oo:!4  of  K  Unit* d  States  gallon. 

29.  The  cajiacity  of  a  sphere,  1  foot  in  diameter,  equals  3.9156 
United  States  gallons. 

:tn.  The  cajiacity  of  a  s])here,  1  inch  in  diameter,  eciuals  .002165 
of  a  United  States  gallon;  hence, 

31.  The  eai)acity  of  any  otlier  (  ylind.r  in  United  States  gallons 
is  obtained  l)y  niultii)lying  the  s(|uare  of  its  diuiiieter  by  its 
length,  or  thecapacity  of  any  other  sphere  by  llie  cube  of  its  di- 
ameter, and  by  the  niimber  of  T'nited  States  gallons  contained  08 
above  in  the  unity  of  its  measurement. 


MENSURATION. 


Of  the  Square,  Rectangle,  Cube,  &c. 


15 


1.  The  side  of  a  square  equals  the  square  root  of  its  area. 

2.  The  area  of  a  square  equals  the  square  of  one  of  its  sides. 

3.  The  diagonal  of  a  square  equals  the  square  root  of  twice  the 
sqiiare  of  its  side. 

4.  The  side  of  a  square  is  equal  to  the  square  root  of  half  the 
sqiiare  of  its  diagonal. 

5.  The  side  of  a  square  equal  to  the  diagonal  of  a  given  square 
contains  double  the  area  of  the  given  square. 

6.  The  area  of  a  rectangle  equals  its  length  multiplied  by  its 
breadth. 

7.  The  length  of  a  rectangle  equals  the  area  divided  hj  the 
breadth;  oi",  the  breadth  equals  the  area  divided  by  the  length. 

8.  The  side  or  end  of  a  rectangle  equals  the  square  root  of  the 
sum  of  the  diagonal  and  oj^posite  side  to  that  required,  multi- 
plied by  their  difference. 

9.  The  diagonal  in  a  rectangle  equals  the  square  root  of  the 
sum  of  the  squares  of  the  base  and  i^erpendicular. 

10.  The  solidity  of  a  cube  equals  the  area  of  one  of  its  sides 
multiplied  by  the  length  or  breadth  of  one  of  its  sides. 

11.  The  length  or  breadth  of  a  side  of  a  cube  equals  the  cube 
root  of  its  solidity. 

12.  The  capacity  of  a  12-inch  cube  equals  7.4784  United  States 
gallons. 


Svirfaces  and  Solidities  of  the  Regular  Bodies,  each 
of  whose  Boundary  Lines  is  1. 


No.  of  Sides. 

Karnes. 

Surfaces. 

Solids. 

4 

6 

8 

12 

20 

Tetrahedron. 

Hexahedron. 

Octahedron. 

Dodecahedron. 

Icosahedron. 

1.7321 
6. 

3.4641 

20.6458 

8.6603 

0.1179 
1. 

0.4714 
7.6631 
2.1817 

The  tabular  surface,  multiplied  by  the  square  of  one  of  the 
boimdary  lines,  eqiaals  the  surface  re<|uired ;  or, 

The  tabular  solidity,  multiplied  by  the  cube  of  one  of  the 
boundary  lines,  equals  the  solidity  required. 


Of  Triangles,  Polygons,  &c. 

1.  The  complement  of  an  angle  is  its  defect  from  a  right  angle. 

2.  The  supplement  of  an  angle  is  its  defect  from  two  right 
angles. 


16 


MENSURATION. 


3.  The  sine,  tangent,  and  secant  of  an  angle  are  the  cosine,  co- 
tangent, and  cosecant  of  the  complement  of  that  angle. 

4.  The  hypotenuse  of  a  right-angled  triangle  being  made 
radii,  its  sides  become  the  sines  of  the  opposite  angles,  or  the 
cosines  of  the  adjacent  angles. 

5.  The  three  angles  of  every  triangle  are  equal  to  two  right  an- 
gles; hence  the  oblique  angles  of  a  right-angled  triangle  are  each 
other's  complements. 

6.  The  sum  of  the  squares  of  the  two  given  sides  of  a  right- 
angled  triangle  is  equal  to  the  square  of  the  hypotenuse. 

7.  The  difl'erencG  between  the  scjuaros  of  the  hypotenuse  and 
given  side  of  a  right-anghnl  triangle  is  equal  to  the  square  of  the 
required  side. 

8.  The  area  of  a  triangle  equals  half  the  product  of  the  base 
multiplied  by  the  perpendicular  height;  or, 

9.  The  area  of  a  triangle  equals  half  the  product  of  the  two 
sides  and  the  natural  sine  of  the  contained  angle. 

10  The  side  of  any  regular  polygon,  uiuitii)lied  by  its  apothegm 
or  perpendicular,  and  by  the  number  of  its  sides,  equals  twice 
the  area- 


Table  of  the  Arecs  of  Regular  Polygons,  each  of 
whose  sides  is  Unity. 


Name 

No.  of 

Apothegm  or 

Area  wlien 

Interior 

Central 

of  Polygon. 

Sides. 

I'erpeud'lar. 

Side  is  Unity. 

Angle. 

Anglo. 

Triangle.  . . . 

3 

0.2887 

0.4330 

00°    0' 

120°  0' 

Square.    .  . . 

4 

C.5 

1 

'JO     9 

90     0 

Pentagon.  . . 

5 

0. 0882 

1.7205 

108     0 

72     0 

Hexagon  .  .  . 
Heptagfin. . 

C 

0.8000 

2.r/J81 

120     0 

GO     0 

7 

1  0380 

3.G339 

128  34 « 

51  25if 

Octagon .... 

H 

1.2071 

4  8284 

135     0 

45     0 

Nonagoii    . 

'.) 

1.3737 

0.1818 

140     0 

40     0 

Decagon. , . 

10 

l.r,388 

7.0'.)42 

144     0 

30     0 

Undecagon 

11 

1.7'  28 

•».30,^)(; 

147  JOA 

35  43,^1 

Dodecagon  . 

12 

1.8000 

11.1'.>02 

150    0 

30     0 

'I'lu^  tabular  area  of  the  corrcKiMiTiding  jiolygnii,  muKiplied  by 
the  square  tif  tlie  side  of  llie  given  polygon,  equals  the.  area  of 
the  given  i)olygon. 


Of  Ellipses,  Cones,  Frustums,  &c. 

1.  Th«)  Kijuiirc  root  of  half  the  sum  of  the  Kijuares  of 
iiinieterH  of  an  ellipso,  multiplied  by  3.1410,  (Miuals  its 


d 
ferenco, 


the  two 
circum- 


INSTRUMENTAL   ARITHMETIC.  17 

2.  Tlie  prodxict  of  the  two  axes  of  an  ellipse,  multiplied  by 
.7854,  equals  its  area. 

3.  The  curve  surface  of  a  cone  is  equal  to  half  the  product  of 
the  circumference  of  its  base  multiplied  by  its  slant  side,  to  which, 
if  the  area  of  the  base  be  added,  the  sum  is  the  whole  surface. 

4.  The  solidity  of  a  cone  equals  one-third  of  the  product  of  its 
base  multiplied  by  its  altitude  or  height. 

5.  The  squares  of  the  diameters  of  the  two  ends  of  the  frustum 
of  a  cone  added  to  the  product  of  the  two  diameters,  and  that  sum 
multiplied  by  its  height  and  by  .2618,  equals  its  solidity. 


INSTRUMENTAL  AKITHMfeTIC, 

Or  Utility  of  the  Slide  Rule. 

The  slide  rule  is  an  instrument  by  which  the  greater  portion  of 
operations  in  arithmetic  and  mensuration  may  be  advantage- 
ously performed,  provided  the  lines  of  division  and  gauge  points 
be  made  properly  correct,  and  their  several  values  familiarly  un- 
derstood. 

The  lines  of  division  are  distingnishe  d  by  the  letters  a  b  c  d; 
A.  B  and  c  being  each  divided  alike,  and  containing  what  is  termed 
a  double  radius,  or  double  series  of  logarithmic  ntxmbers,  each 
series  being  supposed  to  be  divided  into  1,000  equal  parts,  and 
distributed  along  the  radius  in  the  following  manner: 

From  1  to  2  contains  301  of  those  parts,  being  the  log.  of  2. 
"         3        "        477  "  "  3, 

4  "        602  "  "  4. 

5  "  699  "  "  5, 
"  6  "  778  "  "  6. 
"         7        "        845              "                          "  7. 

8  "        903  "  "  '    8. 

9  "        954  "  "  9. 

1,000  being  the  whole  number. 

The  line  d  on  the  improved  rules  consists  of  only  a  single  ra- 
diias;  and  although  of  larger  radiiis,  the  logarithmic  series  is  the 
same,  and  disposed  of  along  the  line  in  a  similar  proportion, 
forming  exactly  a  line  of  square  roots  to  the  numbers  on  the 
lines  B  c. 


Numeration. 

Numeration  teaches  us  to  estimate  or  i^roperly  value  the  num- 
bers and  divisions  on  the  rule  in  an  arithmetical  form. 

Their  values  are  all  entirely  governed  by  the  value  set  upon 
the  first  figure,  and,  being  decimally  reckoned,  advance  tenfold 
from  the  commencement  to  the  termination  of  each  radius:  thus, 
suppose  1  at  the  joint  be  one,  the  1  in  the  middle  of  the  rule  is 


18  INSTRUMENTAL  ARITHMETIC. 

ten,  and  1  at  the  end,  one  hundred  ;  again,  suppose  1  al  the 
joint  ten,  1  in  the  middle  is  100,  and  1  or  ten  at  the  end  is  1,000, 
&c.,  the  intermediate  divisions  on  which  completes  the  whole 
system  of  its  notation. 

To  Multiply  Numbers  by  the  Hule. 

Set  1  on  B  opposite  to  the  multiplier  on  a;  and  against  the  num- 
ber to  be  multiplied  on  b  is  the  product  on  a. 

Multiply  6  by  4. 

Set  1  on  B  to  4  on  a;  and  against  G  on  b  is  24  on  a. 

The  slide  thiis  set,  against  7  on  b  is  28  on  a. 

8  "       32    " 

9  "  3fi  " 
10  "  40  " 
12  "  48  " 
15       "       GO    " 

25       "     100    "    &c. 


To  Divide  Numbers  upon  the  Rule. 

Set  the  divisor  on  b  to  1  on  a  ;  and  against  the  number  to  be 
divided  on  b  is  the  quotient  on  a. 

Divide  63  by  3. 

Set  3  on  n  to  1  on  a;  and  against  63  ou  b  is  21  on  a. 


Proportion,  or  Rule  of  Three  Direct. 

Rule. — Sit  the  first  term  on  b  to  the  second  on  a;  and  against 
the  third  upon  b  is  the  fourth  uj^on  a. 

1.  If  4  yards  of  cloth  cost  38  cents,  what  will  30  yards  cost  at 
the  same  rate  ? 

Set  4  on  b  to  38  on  a;  and  against  30  on  n  is  285  cents  on  a. 

2.  Suj)j)os<;  I  pay  31  dollars  50  cents  for  3  cwt.  of  copper,  at 
what  rate  is  tliat  jx-r  ton?     1  /o?( ,=;  20  net. 

Set  3  upon  b  to  31.5  upon  a;  and  against  20  upon  n  is  210  upon  a. 


Rule  of  Three  Inverse. 

Rule. — Invert  the  sliile,  and  the  operation  is  the  same  as  direct 
proportion. 

1.  I  know  that  six  men  are  capabh'  of  pcrforiuing  a  certain 
given  portion  of  work  in  <iglit  days,  but  1  want  tlie  same  j)er- 
forrned  in  tlirer;  how  many  men  must  there  be  employed? 

Set  6  upon  c  to  8  upon  a;  and  against  •')  upon  c  is  Ki  upon  a. 

2.  The  lever  of  a  safety-valve  is  20  iiuilies  in  length,  and  5 
inches  between  the  fixed  end  and  eentn'  of  the  valve ;  what 
w*!ight  must  there  be  placed  on  the  lower  end  of  the  lever  to  equi- 
jjrtisr  a  fiin^i'  or  pressure  of  40  lbs.,  tending  to  raise  tlie  valve? 

Set  5  up(ju  c  to  10  uj>ou  a;  uud  against  20  upon  c  is  10  upon  A. 


INSTRUMENTAL    ARITHMETIC.  19 

3.  If  8|  yards  of  cloth,  1 J  yards  in  width,  be  a  sufficient  quan- 
tity, how  much  will  be  required  of  that  which  is  only  7-8th3  in 
width,  to  effect  the  same  purpose? 

Set  1.5  upon  c  to  8.75  upon  a;  and  against  8.75  upon  c  is  15 
yards  upon  a. 

Square  and  Cube  Boots  of  Numbers. 

On  the  engineer's  rule,  when  the  lines  c  and  d  are  equal  at  both 
ends,  c  is  a  table  of  squares,  and  d  a  table  of  roots,  as 

Squares  1    4    9     16    25     36    49     64    81  on  c. 
Boots      12    3     4      5      6      7      8      9    on  d. 


To  find  the  Geometrical  Mean  Proportion  between 

two  Numbers. 

Set  one  of  the  numbers  upon  c  to  the  same  niimber  upon  d; 
and  against  the  other  number  upon  c  is  the  mean  number  or  side 
of  an  equal  square  upon  d. 

Required  the  mean  proportion  between  20  and  45. 

Set  20  upon  c  to  20  upon  d;  and  against  45  upon  c  is  30  upon  d. 

To  cube  any  number,  set  the  number  upon  c  to  1  or  10  upon  d; 
and  against  the  same  number  upon  d  is  the  cube  number  upon  c. 

Required  the  cube  of  4. 

Set  4  upon  c  to  1  or  10  upon  d;  and  against  4  upon  d  is  64 
upon  c. 

To  extract  the  cube  root  of  any  number,  invert  the  slide  and 
set  the  number  upon  b  to  1  or  10  upon  d;  and  where  two  num- 
bers of  equal  value  coincide  on  the  lines  b  d  is  the  root  of  the 
given  number. 

Required  the  cube  root  of  64. 

Set  64  upon  b  to  1  or  10  upon  d;  and  against  4  upon  b  is  4 
upon  D,  or  root  of  the  given  number. 

On  the  common  rule,  when  1  in  the  middle  of  the  line  c  is  set 
opposite  to  10  on  d,  then  c  is  a  table  of  squares,  and  d  a  table  of 
roots. 

To  cube  any  niimber  bj^  this  rule,  set  the  number  upon  c  to  10 
upon  n;  and  against  the  same  number  upon  d  is  the  cube  upon  c. 


Mensuration  of  Surface. 
1.  Squares,  Rectangles,  <f*c. 

Rule.  —When  the  length  is  given  in  feet  and  the  breadth  in 
inches,  set  the  breadth  on  b  to  12  on  a;  and  against  the  length 
on  A  are  the  contents  in  square  feet  on  b. 

If  the  dimensions  are  all  inches,  set  the  breadth  on  b  to  144 
upon  a;  and  against  the  length  upon  a  is  the  number  of  square 
feet  on  b. 


20 


INSTRUMENTAL    ARITHMETIC. 


Required  the  contents  of  a  board  15  inches  broad  and  14  feet 
long. 

Set  15  upon  b  to  12  upon  a;  and  against  14  upon  a  is  17,5 
square  feet  on  b. 

2.  Circles,  Polygons,  d;c. 

Rule.— Set  .7854  upon  c  to  1  or  10  upon  r>;  then  will  the  lines 
c  and  D  be  a  table  of  areas  and  diameters. 

Areas  3.14  7.06  12.56  19.63  28.27  38.48  50.26  63.61  upon  c. 

Diam.  2        3456789       upon  d. 

In  the  common  rule,  set  .7854  on  c  to  10  on  n;  then  c  is  a  line 
or  table  of  areas,  and  n  of  diameters,  as  before. 

Set  7  upon  b  to  22  ujjon  a;  then  b  and  a  form  or  become  a  table 
of  diameters  and  circumferences  of  circles. 

Cir.  3.14  6.28  9.42  12.56  15.7  18.85  22  25.13  28.27  upon  a. 

I>ia.  123  4         56  78         9       upon  b. 

Polygons  from  3  to  12  Sides.-^et  the  gauge-point 
upon  c  to  1  or  10  upon  v;  and  against  the  length  of  one  side 
upon  D  is  the  area  upon  c. 

Sides  3     5      6      7       8       9         10      11      12 

Gauge-points  .433  1.7  2.6  3.63  4.82  6.18     7.69  9.37  11.17 

Required  the  area  of  an  equilateral  triangle,  each  side  12 
inches  in  length. 

Set  .433  upon  c  to  1  upon  n;  and  against  12  ujwn  d  are  62.5 
square  inches  upon  c. 


Table  of  Gauge-Points  for  the  Engineer's  Rule. 


Names. 

F,  F,  F. 

F,  I,  I. 

I,  I,  I. 

F,  I. 

I,  I. 

F. 

I. 

Cubic  inches. . 

578 

83 

1728 

106 

1273 

105 

121 

Cubic  feet .... 

1 

144 

1 

1833 

22 

121 

33 

Imp.  gallons.  . 

163 

231 

277 

294 

353 

306 

529 

Watfr  in  lbs. . 

16 

23 

270 

293 

352 

305 

528 

Gold 

814 

1175 

141 

149 

178 

155 

269 

Silver    " 

15 

216 

261 

276 

334 

286 

5 

Mercury  " 

lis 

109 

203 

216 

258 

225 

3H9 

JJrass 

193 

177 

333 

354 

424 

3(;9 

637 

CopJXT    " 

18 

26 

319 

331 

397 

345 

596 

Lwnl 

141 

203 

243 

258 

31 

27 

465 

Wro't  iron  " 

207 

297 

357 

338 

453 

394 

682 

Cast  ircju  " 

222 

32 

3HI 

407 

4H9 

421 

733 

Tin 

219 

315 

378 

401 

481 

419 

728 

Strcl 

202 

292 

352 

372 

418 

385 

671 

Coal 

127 

1H3 

22 

33 

28 

242 

42 

Miirbl.) 

591 

85 

102 

116 

13 

113 

195 

Froehtono  " 

•  G32 

015 

11 

1102 

14 

141 

21 

<» 


INSTRUMENTAL    ARITHMETIC. 


21 


For  the  Common  Slide  Riile. 

Names. 

F,  F,  F. 

F,  I,  I. 

I,  I,  I. 

F,  I. 

1,1. 

F. 

I. 

Cubic  inches. 

36 

618 

624 

669 

799 

625 

113 

Cubic  feet .... 

G25 

9 

108 

114 

138 

119 

206 

Water  in  lbs. . 

10 

144 

174 

184 

22 

191 

329 

Gold 

507 

735 

88 

96 

118 

939 

180 

Silver 

938 

136 

157 

173 

208 

173 

354 

Mercury     " 

738 

122 

127 

132 

162 

141 

242 

Brass           ' ' 

12 

174 

207 

221 

265 

23 

397 

Copper        " 

112 

163 

196 

207 

247 

214 

371 

Lead           " 

880 

126 

152 

162 

194 

169 

289 

Wro't  iron  " 

129 

186 

222 

235 

283 

247 

423 

Cast  iron    " 

139 

2 

241 

254 

304 

265 

458 

Tin 

137 

135 

235 

25 

300 

261 

454 

Steel 

136 

183 

22 

233 

278 

239 

418 

Coal 

795 

114 

138 

116 

176 

151 

262 

Marble        " 

370 

53 

637 

725 

81 

72 

121 

Freestone   " 

394 

57 

69 

728 

873 

755 

132 

Mensuration  of  Solidity  and  Capacity. 

General  Eule. — Set  the  length  upon  b  to  the  gauge-point 
upon  a;  and  against  the  side  of  the  square,  or  diameter  on  d,  are 
the  cubic  contents,  or  weight  in  lbs.  on  c. 

1.  Required  the  cubic  contents  of  a  tree,  30  feet  in  length  and 
10  inches  quarter  girt. 

Set  30  upon  b  to  144  (the  gauge-point)  upon  a;  and  against  10 
upon  D  is  20. 75  feet  upon  c. 

2.  In  a  cylinder,  9  inches  in  length  and  7  inches  diameter,  how 
many  cubic  inches? 

Set  9  upon  b  to  1273  i^tlie  gauge-point)  upon  a;  and  against  7 
on  D  is  346  inches  on  c. 

3.  ^liat  is  the  M-eight  of  a  bar  of  cast  iron,  3  inches  square  and 
6  feet  long  ? 

Set  6  upon  b  to  32  (the  gauge-point)  upon  a;  and  against  3 
upon  D  is   16S  pounds  i;pon  c. 
By  the  Common  Rule. 

4.  Required  the  weight  of  a  cylinder  of  wrought  iron,  10 
inches  long  and  5^  diameter. 

Set  1!)  upon  B  to"  283  (the  gauge-point)  upon  a;  and  against  5^ 
upon  D  is  66.63  pounds  on  c. 

5.  What  is  the  weight  of  a  dry  rope,  25  yards  long  and  4  inches 
circumference  ? 

Set  25  upon  b  to  47  (the  gauge-point)  upon  a;  and  against  4  on 
D  is  53. 16  pounds  on  c. 

6.  What  is  the  weight  of  a  short-linked  chain,  30  yards  in 
length  and  6-16ths  of  an  inch  in  diameter? 

Set  30  upon  b  to  52  (the  gauge-point)  upon  a;  and  against  C  on 
D  is  129.5  pounds  on  c. 


22  MANUFACTURE    OF   TIX    PLATE. 

Power  of  Steam-Engines. 

Condensing  Engines.  IIole  — Set  3.5  on  c  to  10  on  d; 
then  n  is  a  line  of  diamt'ters  for  cylinders,  and  c  the  corresjiond- 
ing  number  of  horses'  power;  thus, 

H.  rr.  3.\       d     5      6      8     10    1-2     16   20    25     30    40     50  on  c. 
CD.  10  in.  10^-  12  U\  15.^  17  18J  2U  24  26^  29i  33|  37|onD. 

The  same  is  eflfected  on  the  common  riile  by  setting  5  on  c  to 
12  on  D. 

Non-Condetiaing  Engines.  ErnE. — Set  the  jiressure  of 
steam  in  pounds  per  S(juarc  inch  on  b  to  4  upon  a;  and  against 
the  cylinder's  diameter  on  n  is  the  number  of  horses'  power  on  c. 

Ilequired  the  power  of  an  engine  when  the  cylinder  is  20 
inches  diameter  and  steam  30  pounds  per  square  inch. 

Set  30  on  B  to  4  on  a;  and  against  20  on  n  is  30  horses'  power 
on  c. 

The  same  is  effected  on  the  common  rule  by  setting  the  force 
of  the  steam  on  b  to  25  J  on  x. 


Of  Engine  Boilers. 

How  many  superficial  feet  are  contained  in  a  boiler,  23  feet  in 
length  and  5.V  feet  in  depth  ? 

Set  1  on  B  to  23  on  a;  and  against  5.5  upon  b  is  12G.5  square 
feet  upon  a. 

If  5  square  feet  of  boiler  surface  be  sufficient  for  each  horse- 
power, how  many  horses'  power  of  engine  is  the  boiler  equal  to  ? 

Set  5  upon  b  to  120.5  upon  a;  and  against  1  upon  b  is  25.5 
upon  A. 


MANUFACTURE  OF  TIN  PLATE. 


Tlio  different  jjrocosscs  in  the  mannfacturo  of  tin  jilato  may  bo 
descriljed  most  ])rnp(M"ly  in  seven  distinct  stages.  The  first  begins 
with  the  bars  of  iron  which  form  tlie  plate  ;  the  last  terminates 
with  an  account  of  tlie  process  of  tinning  their  surface.  The 
d(Sfri)>tion  is  souxwliat  technical ;  but  a  glance  at  the  following 
hcails  will  ciiubln  the  reader  to  comprehi'iid  the  whole  process: 

1.  lio/ling  is  the  first  and  most  important  jioint  requisite 
to  the  i)rodnction  of  the  lulten,  or  jjlatis  of  iron,  i)revious  to  the 
operation  of  tinning  them.  Fortius  purpose  the  finest  quality 
of  charcoal  iron  is  invariably  employed,  which,  in  its  commercial 
htate,  generally  consists  of  long  flat  bars.  'J'liese  are  cut  into 
small  squares  averaging  one-half  an  iniOi  in  tl-.iclaiess,  which  are 
heated  n  peatedly  in  a  furnace,  ami  are  npcatedly  i)assing  through 
iron  rollers.  A  convenient  degree  of  thinness  having  been  ob- 
tained, the  now  extended  plates  arc  "doubled  up,"  heated,  rolled, 


MANUFACTURE    OF   TIN   PLATE.  23 

opened-oiit,  heated  and  rolled  again,  until,  at  length,  the  stan- 
dard thickness  of  the  plate  has  been  reached. 

2.  Shearing . — A  pair  of  massive  shears  worked  by  machin- 
ery, is  no\Y  applied  to  the  ragged  edges  of  this  lamellar  formation 
of  iron-plate.  It  is  ciit  into  oblong  squares,  1-i  inches  by  10,  s.nd 
presents  the  appearance  of  a  single  plate  of  iron,  beautifully 
smooth  on  its  surface.  A  juvenile  with  a  knife  soon  destroys  the 
appearance,  however,  and  eight  j^lates  are  produced  from  the 
slightly  coherent  mass. 

3.  Scaling. — This  process  consists  in  freeing  the  iron  sur- 
face from  its  oxide  and  scoria;.  After  an  application  of  sulphuric 
acid,  a  number  of  plates,  to  the  extent,  we  shall  say,  of  600  or 
800,  are  packed  in  a  cast-iron  box,  which  is  exposed  for  some 
hours  to  the  heat  of  a  furnace.  On  being  opened  the  plates  are 
found  to  have  acqiiired  a  bright  blue  steel  tint,  and  to  be  free 
from  surface  impurities. 

4:.  Cold  Rolling. — It  is  impossible  that  the  plates  could 
pass  through  the  last  fiery  ordeal  without  becoming  disfigured. 
The  cold  rolling  process  corrects  this.  Each  plate  is  separately 
passed  through  a  pair  of  hard  polished  rollers,  screwed  tightly 
together.  Not  only  do  the  plates  acquire  from  this  operation  a 
high  degree  of  smoothness  and  regularity,  but  they  likewise  ac- 
quire the  peculiar  elasticity  of  hammered  metal.  One  man  will 
cold  roll  225,000  plates  in  a  week,  and  each  of  them  is,  on  an 
average,  three  times  passed  through  the  rollers. 

5.  A.nnealing. — This  process  is  also  a  modern  improvement 
on  the  manufacture:  GOO  plates  are  again  packed  into  cast-iron 
boxes  and  exposed  to  the  furnace.  There  is  this  difference  in 
the  present  process  from  that  of  scaling — that  the  boxes  must  be 
preserved  air-tight,  otherwise  the  contained  plates  would  inevi- 
tably weld  together  and  produce  a  solid  mass.  The  infinitessinial 
portion  of  confined  air  j^revents  this. 

6.  Fielding. — The  plates  are  again  confined  in  a  bath  of 
diluted  acid,  till  the  surface  becomes  uniformly  bright  and  clean. 
Some  nice  manipulation  belongs  to  this  process.  -  Each  plate  is, 
on  its  removal  from  the  acid,  subjected  to  a  rigid  scrutiny  bj' 
women,  whose  vocation  it  is  to  detect  any  remaining  impurity, 
and  scour  it  fi'om  the  surface.  The  multifarious  operations,  it 
will  be  seen,  are  all  preliminary  to  the  last,  and  the  most  im- 
portant of  all — that  of  tinning.  Theoreticallj'  simple,  this  pro- 
cess is  practically  difficult,  and  to  do  it  full  justice  would  carry 
us  beyond  oiir  limits.  We  shall,  however,  mention  the  j)rincipal 
features. 

7.  Tinning, — A  rectangular  cast-iron  bath,  heated  from 
below,  and  calculated  to  contain  200  or  30J  sheets,  and  about  a 
ton  of  piire  block  tin,  is  now  put  in  request.  A  stratum  of  pyreia- 
matic  fat  floats  upon  its  surface.  Close  to  the  side  of  this  tin  pot 
stands  another  receptacle,  which  is  filled  with  melted  grease,  and 
contains  the  prepared  plates.  On  the  other  side  is  an  empty  pot, 
with  a  grating  ;  and  last  of  all  there  is  yet  another  pot,  contain- 
ing a  small  stratum  of  melted  tin.  Let  us  follow  the  progress  of 
a  single  plate.     A  functionary   known  as   the    "washerman," 


24  MANUFACTURE    OF    TIN   PLATE. 

armed  with  tongs  anil  a  liempen  brush,  withdraws  the  plate  from 
the  bath  of  tin  wherein  it  has  been  soaking;  and,  with  a  dexterity 
only  to  be  acquired  by  long  practice,  sweeps  one  side  of  tho 
plate  clean,  and  then  reversing  it,  repeats  the  operation.  In  an 
instant  it  is  again  submerged  in  the  liquid  tin,  and  is  then  as 
quickly  transferred  to  the  liquid  grease.  The  peculiar  use  of 
the  hot  grease  consists  in  the  property  it  possesses  of  equalizing 
the  distribution  of  the  tin,  of  retaining  the  suiJerfliious  metal, 
and  of  spreading  the  remainder  equally  on  the  surface  of  the 
iron.  Still  there  is  left  on  the  plate  what  we  may  term  a  salvage; 
and  this  is  finallj'  removed  bj'  means  of  the  last  tin  pot,  which 
just  contains  the  necessary  quantity  of  fluid  metal  to  melt  it  oft' — a 
smart  blow  being  given  at  the  same  moment  to  assist  the  disen- 
gagement. The  "list-mark"  may  be  observed  upon  every  tin 
plate  without  exception.  We  may  add  hei'e,  that  an  expert  wash- 
erman will  finish  (;,()()0  metallic  plates  in  twelve  hours,  notwith- 
standing that  each  plate  is  twice  washed  on  both  sides,  and  twice 
dipped  into  the  melted  tin.  After  some  intermediate  ojierations 
— for  we  need  not  continue  the  consecutive  description — the 
plates  are  sent  to  tho  final  operation  of  cleaning.  For  this  pur- 
pose they  are  rubbed  with  bran,  and  dusted  ujion  tables;  after 
which  they  present  the  beautiful  silvery  appearance  so  character- 
istic of  the  best  English  tin  plate.  Last  of  all  thej'  reach  an  in- 
dividual called  the  "sorter,"  who  subjects  every  plate  to  a  strict 
examination,  rejects  those  which  are  found  to  be  defective,  and 
sends  those  which  are  approved  to  be  packed,  300  at  a  time,  in 
the  rough  wooden  boxes,  with  the  cabalistic  signs  with  which 
most  of  us  have  been  familiar  since  the  days  of  our  adventures 
in  the  back-shop  of  the  tinsmith. 


Quality  of  Tin  Plate. 

The  tests  for  tin  plates  are  ductility,  strength,  and  color  ;  and 
to  po.ssess  these,  the  iron  used  must  be  of  the  best  (pialit}',  and 
all  the  process  be  conducted  with  care  and  skill.  The  following 
conditions  are  inserted  in  some  sjx'cifii^ations,  and  will  serve  to 
indicate  the  strtiiigth  and  ductility  of  first-class  tin  platens: 

1st.  Thi'y  must  bear  cutting  into  strips  of  a  width  e([ual  to  ten 
times  th(!  tliiirkmss  of  the  i)late,  both  with  and  across  tlie  fibre, 
witliout  splitting;  tho  strips  must  bear,  while  hot,  ix-ing  bent 
upon  a  mould,  to  a  sweep  cc^ual  to  four  times  the  width  of  tho 
strip. 

2d.  While  cold,  the  jdates  must  bear  l)en<ling  in  a  heading 
niacliiiie,  in  such  a  manner  as  ti)  fdriii  a  cylinder,  tlie  diameter 
of  which  shall  at  most  bi;  equal  to  sixty  times  the  thicl<riess  of 
the  jilate.  In  these  tests,  the  jtlate  must  show  neither  Haw  nor 
crack  of  any  kind. 


Crytallizcd  Tin-Plato. 
Crystallized  tin-i>hite  is  a  variegntitd  primrose  appearancre,  pro- 
duced upon  the  surface  of  tin  ]>late  by  ai)i>lying  to  it  in  a  heated 
state  some  dilute   nitro-muriatic  acid   for  a  few  seconds,  then 


MAXtTFACTUEE   OF   TIN   PLATE.  25 

•washing  it  with  water,  dn-ing,  and  coating  it  with  lacquer.  The 
figures  are  more  or  less  beautiful  and  diversitied,  according  to 
the  degree  of  heat  and  relative  dilution  of  the  acid.  Place  the 
tin  plate,  slightly  heated,  over  a  tub  of  water,  and  rub  its  surface 
with  a  sponge  dipped  in  a  liquor  composed  of  four  parts  of  aqua- 
fortis, and  two  of  distilled  w.ter,  holding  one  part  of  common 
salt  or  sal  ammoniac  in  solution.  Whenever  the  crystalline 
spangles  seem  to  be  thoroughly  brought  out,  the  plate  must  be 
immersed  in  water,  washed  either  with  a  feather  or  a  little  cotton 
(taking  care  not  to  nib  off  t)ie  film  of  tin  that  forms  the  feather- 
ing), forthwith  dried  with  e,  low  heat,  and  coated  with  a  lacquer 
varnish,  otherwise  it  loses  its  lustre  in  the  air.  If  the  whole 
surface  is  not  plunged  at  cnce  in  cold  water,  but  if  it  be  partial- 
ly cooled  by  sprinkling  v.  ater  on  it,  the  crystallization  will  be 
finely  variegated  with  large  and  small  figures.  Similar  results 
will  be  obtained  by  blowing  cold  air  through  a  pipe  on  the  tinned 
surface,  while  it  is  just  passing  from  the  fused  to  the  solid  state. 


Tinning. 

1.  Plates  or  vessels  of  brass  or  copper,  boiled  with  a  solution 
of  stannate  of  potassa,  mixed  with  turnings  of  tin,  become,  in  the 
course  of  a  few  minutes,  covered  with  a  firmly  attached  layer  of 
pure  tin.  2.  A  similar  effect  is  produced  by  boiling  the  articles 
■ftith  tin  filings  and  caustic  alkali,  or  cream  of  tartar.  In  the 
above  way,  chemical  vessels  made  of  copper  or  brass  may  be  easily 
and  perfectly  tinned. 


New  Tinning  Process. 

The  articles  to  be  tinned  are  first  covered  with  dilute  siilphuric 
acid,  and  when  quite  clean  are  placed  in  warm  water,  then  dip- 
ped in  a  solution  of  miiriatic  acid,  copper,  and  zinc,  and  then 
plunged  into  a  tin  bath  to  which  a  small  quantity  of  zinc  has 
been  added.  When  the  tinning  is  finished,  the  articles  are  taken 
out  and  plunged  into  boiling  water.  The  operation  is  completed 
by  placing  them  in  a  very  warm  sand  bath.  This  last  process 
softens  the  iron. 


Kustitien's  Metal  for  Tinning. 

Malleable  iron  1  pound,  heat  to  whiteness;  add  5  ounces  regulus 
of  antimony,  and  Molucca  tin  2i  pounds. 


Capacity  of  Cans  One  Inch  Deep. 

UTILITY  OF  THE  TABLE. 

Eequired  the  contents  of  a  vessel,  diameter  G  7-lOths  inches, 
/iepth  10  inches. 

By  the  table  a  vessel  one  inch  deep,  and  6  and  7-lOths  inches 
iiameter  contains  .15  (hundredths)  of  a  gallon,  then  .15  X  10  = 
1.50  or  1  gallon  and  2  quarts. 

2 


20 


CAPACITY   OF    CANS   IX   GALLON'S. 


EequiretT  the  contents  of  a  can,  tliaineter  19  8-lOtlis  inches, 
depth  3U  inches. 

By  the  table  a  vessel  1  inch  deep  and  19  and  8-lOths  inches  di- 
ameter contains  one  gallon  and  .'d'3  thundrcdths),  then  1.33  X  30 
=  39.90  or  nearly  -10  gallons. 

Hequired  the  depth  of  a  can  whose  diameter  is  12  and  2-lOths 
inches,  to  contain  Ki  gallons. 

By  the  table  a  vessel  1  inch  deep  and  12  and  2-lOths  inches  di- 
ameter contains  .50  (hundredths  of  a  gallon),  then  IG  -i-  .50  =  32 
inches,  the  depth  recpiired,  viz. : 

.50  )  16  (  32  X  .50  =  IG  gallons. 


Diim.  ' 

!_ 

2 

3 

_4 

a 

6 

T 

a. 

9 

etifr. 

.03 

10 

10 

i  0 
.03 

iO 

15 

10 

10 

io 

10 

3 

.03 

.03 

.03 

.04 

.04 

.04 

.04 

.05 

4 

.05 

.05 

.05 

.05 

.06 

.06 

.07 

.07 

.07 

.(8 

5 

.08 

.08 

.08 

.09 

.09 

.10 

.10 

.11 

.11 

.11 

6 

.12 

.12 

.12 

.13 

.13 

.U 

.14 

.15 

.15 

.16 

7 

.16 

.17 

.17 

.18 

.18 

.19 

.19 

.20 

.20 

.21 

8 

.21 

.22 

.22 

.'J  3 

.23 

.24 

.25 

.25 

.26 

.26 

9 

.27 

!28 

.28 

.29 

.30 

.30 

.31 

.31 

.32 

.33 

10 

.34 

.34 

.35 

.36 

.36 

•37 

.38 

.38 

.39 

.40 

11 

.41 

.41 

.42 

.43 

.44 

.41 

.45 

.46 

.47 

.48 

12 

.48 

.49 

.50 

.51 

.52 

.53 

.53 

.54 

55 

.50 

13 

.57 

.58 

.59 

.60 

.60 

.61 

.62 

.63 

.64 

.65 

U 

.66 

.67 

.68 

.69 

.70 

.71 

.72 

.73 

.74 

.75 

15 

.76 

.77 

.78 

.79 

.80 

.81 

.82 

.83 

.84 

.85 

16 

.87 

88 

.89 

.9t) 

.91 

.92 

.93 

.94 

.95 

.97 

17 

.98 

.99 

1.005 

1.017 

1.028 

1.040 

1.051 

1.06.! 

1.075 

1.086 

18 

1.101 

1.113 

1  125 

1.138 

1.150 

1.162 

1.170 

1.187 

1.200 

1.211 

19 

1.227 

1.240 

1.253 

1.266 

1.279 

1.292 

1.304 

1.317 

1.330 

1.343 

20 

1.360 

1.373 

1.385 

1.400 

1.414 

1.128 

1.441 

1.455 

1.478 

1.4S2 

21 

1.199 

1.513 

1.527 

1.542 

1.55(; 

1.570 

1.585 

1.600 

1.612 

1.630 

22 

1.645 

1.660 

1.G75 

1.696 

1.705 

1.720 

1.735 

1.750 

1.770 

1.780 

23 

1.798 

1.814 

1.830 

1.845 

l.f-61 

1.876 

1.892 

1.908 

1.923 

1.940 

24 

1.9r,8 

1.974 

1.991 

2.007 

2.023 

2.040 

2.0.56 

2.072 

2.096 

2.103 

25 

2.125 

2.142 

2.159 

2.176 

2.193 

2.210 

2.227 

2.244 

2.261 

2.280 

26 

2.298 

2.316 

2.333 

2.351 

2.369 

2.;i86 

2.404 

2.422 

2.440 

2.460 

27 

2.478 

2.496 

2.515 

2.533 

2.55J 

2.570 

2. 588 

2.607 

2.625 

2.643 

28 

2.665 

2.6H4 

2.703 

2.722 

2.711 

2.764 

2.780 

2.800 

2.820 

2.836 

29 

2.859 

2.879 

2.898 

2.918 

2.93H 

2.958 

2.977 

2.997 

3.017 

3.03G 

30 

3.000 

3.080 

.3.100 

3.121 

3.141 

3.162 

3.182 

3.202 

3.223 

3.245 

31 

3.267 

3. 2HH 

3.  .309 

3.3:!0 

3.351 

3.372 

3.393 

3.414 

3.436 

3.457 

32 

3.181 

3.50:! 

3.524 

3.543 

3.56s 

3.59(» 

3.612 

3.633 

3  655 

3.689 

33 

3  702 

3.725 

3.747 

3.773 

3.79.". 

3.814 

3.h37 

3.860 

3.882 

3.901 

31 

3.93(1 

3.953 

3.976 

4.003 

1.022 

L0I6 

4. 070 

4.092 

4.115 

4.140 

35 

4.165 

4.188 

4.212 

4.236 

4.260 

4.284 

4.31)7 

4  331 

4.355 

4.  .380 

30 

4  406 

4.430 

4.455 

4.48:! 

4.503 

4.. 528 

4.5.53 

4.577 

4.602 

4.62G 

37 

4.6.54 

4.679 

4. 704 

4.730 

•1.7r:5 

4.780 

4.805 

4.834 

4.8.55 

4.880 

38 

4.909 

4.935 

4.961 

4.987 

5. 01 '2 

5.03S 

5.064 

5.090 

5.120 

5.142 

39 

.'i.ni 

5.197 

5.224 

5.2.50 

5.277 

5.30 » 

5.330 

5.357 

.5.383 

5.410 

40 

5.440 

5.467 

5.491 

5.521 

5.548 

5.576 

5.603 

5.630 

5.657 

5.684 

MEASUREMENT  OF  BRICKLAYERS'  WORK.     27 

RULES    AND    TABLES 

For  Computing  the  Wokk  of  Bkickx.atees,  Well-Diggers, 
Masons,  Carpenters  and  Joiners,  Slaters,  Plasterers, 
P.UNTEKS,  Glaziers,  Paters,  and  PLiraiBERS. 


Measurement  of  Bricklayers'  Work. 

Brick-work  is  cslimateJ  at  the  rate  of  a  number  of  bricks  in 
thickness,  estimating  a  brick  at  4  inches  thick.  The  dimensions 
of  a  buililing  are  iisually  taken  by  measuring  half  round  on  the 
outside,  and  half  round  on  the  inside  ;  the  sum  of  these  two  gives 
the  compass  of  the  wall, — to  be  multiplied  by  the  height,  for  the 
contents  of  the  materials.  Chimneys  are  by  some  measured  as  if 
they  were  solid,  deducting  onlj'  the  vacuity  from  the  hearth  to 
the  mantel,  on  account  of  the  trouble  of  them.  And  by  others 
they  are  girt  or  measured  round  for  their  breadth,  and  the 
height  of  the  story  is  their  height,  taking  the  depth  of  the 
jambs  for  their  thickness.  And  in  this  case,  no  deduction  is 
made  for  the  vacuity  from  the  floor  to  the  mantel-tree,  because 
of  the  gathering  of  the  breast  and  wings,  to  made  room  for  the 
hearth  in  the  next  storj'.  To  measure  the  chimney  shafts,  which 
appear  above  the  building,  gird  them  about  with  a  line.for  the 
breadth,  to  multiply  by  tiieir  height.  And  account  their  thick- 
ness half  a  brick  more  than  it  really  is,  in  consideration  of  the 
plastering  and  scaffolding.  All  Avindows,  doors,  &c.,  are  to  be 
deducted  out  of  the  contents  of  the  walls  in  which  they  are  placed. 
But  this  deduction  is  made  only  with  regard  to  materials  ;  for 
the  whole  measure  is  taken  for  workmanship,  and  that  all  out- 
si  le  measure  too,  namely,  measuring  quite  round  the  ou,tside  of 
t'.:e  building,  being  in  consideration  of  the  trouble  of  the  returns 
or  angles.  There  are  also  some  other  allowances,  such  as  double 
measure  for  feathered  gable  ends,  &c. 

Example. — The  end  wall  of  a  house  is  2S  feet  long,  and  37  feet 
high  to  the  eaves  ;  15  feet  high  is  four  bricks  or  16  inches  thick, 
other  12  feet  is  three  bricks  or  12  inches  thick,  and  the  remain- 
ing 10  feet  is  two  bricks  or  8  inches  thick  ;  above  which  is  a 
triangular  gable  12  feet  high  and  one  brick  or  4  inches  in  thick- 
ness. What  number  of  bricks  are  there  in  the  said  wall? 
A)is.  2"),C20. 

7Iiickticss* 
28  X  15  =  420  X  4  =  1680  contents  of  1st  story. 
28X12  =  336X3  =  1008         "         "2d 
28X10  =  280X2=560         "         "3d       " 
:   6X28  =  168X1=    168         "         "gable. 

3416     square  feet  area  of  whole  wall. 
7^  bricks  to  squ.are  foot. 

23,912         By  the  table. 
1,708  3000  SUP.  ft.  =  22,500  bk's 

400    "       "  =   3,000    " 

Answer,       25, 620  bricks.    10    "       "  =         75    " 

6    "       "  =        45    " 

3il6    "       "  =25,620  bk's 


12 


28 


MEASUREMENT    OF    BRICK-WORK, 


A  Table  by  which  to  ascertain  the  number  of  Bricks 
necessary  to  construct  any  Piece  of  Building  from 
a  four-inch  Wall  to  twenty-four  inches  in  Thick- 
ness. 

The  utility  of  the  Table  below  can  be  seen  by  the  following 
Example.  Required  the  number  of  bricks  to  build  a  wall  of  12 
inches  thickness,  and  containing  an  area  of  6,437  square  feet. 


Square  feet  1000 


GOOD: 

400: 

30: 

7: 


22,501  bricks— See  table. 
G 


135,(  00 

9,000 

675 

158 


Note. — 7.1  bricks 
equal  one  superficial  foot. 


6,437=    144,833  bricks. 


Superficial 

Number  of  Bricl 

B  to  Thick 

ness  of 

feet  of 

Wall. 

4-incli. 

8-incU. 

12-inch. 

IG-inch 

20-inch. 

24-inch. 

1 

8 

15 

23 

30 

38 

45 

2 

15 

30 

45 

60 

75 

90 

3 

23 

45 

68 

90 

113 

135 

4 

30 

60 

90 

120 

150 

180 

5 

38 

75 

113 

150 

1S8 

225 

6 

45 

90 

135 

180 

225 

270 

7 

53 

105 

15« 

210 

263 

315 

8 

60 

120 

180 

240 

300 

300 

9 

68 

135 

203 

270 

338 

405 

10 

75 

150 

225 

300 

375 

450 

20 

150 

300 

450 

600 

750 

900 

30 

225 

450 

675 

900 

1125 

1350 

40 

300 

600 

900 

1200 

1.500 

1800 

50 

375 

7o() 

1125 

15n() 

1875 

2250 

60 

450 

900 

1350 

ISOO 

2250 

2700 

70 

525 

1050 

1575 

2100 

2625 

3150 

80 

600 

1200 

1800 

2400 

3000 

3600 

90 

075 

1350 

2025 

2700 

3375 

4050 

100 

750 

1500 

2250 

3000 

3750 

4500 

200 

1500 

3000 

4500 

6000 

7500 

9000 

300 

2250 

4500 

6750 

9000 

112.50 

13500 

400 

30U0 

6000 

9000 

12000 

15000 

18000 

500 

3750 

7500 

11250 

1.5O00 

18750 

22500 

600 

4500 

9000 

13.500 

IHOOO 

22500 

27000 

700 

5250 

10.500 

15750 

2 1 000 

26250 

31500 

«00 

6000 

12000 

18000 

24000 

30000 

36000 

900 

(;750 

13.500 

20250 

27000 

33750 

40500 

1000 

7500 

1.5000 

22500 

30000 

37500 

45000 

MEASUREMEKT   OF    WELLS,   ETC.  29 

Measurement  of  Wells  and  Cisterns. 

There  are  two  methods  of  estimating  the  value  of  excavating. 
It  may  be  done  by  allowing  so  much  a  day  for  every  man's  work, 
or  so  much  per  cubic  foot,  or  yard,  for  all  that  is  excavated. 

Well  Digging.— SuppofiB  a  well  is  40  feet  deep,  and  5  feet 
in  diameter,  required  the  number  of  cubic  feet,  or  yards. 
5  X  5  =  25  X  .7854  =  19.635  X  40  =  785.4  cubic  feet. 

Sujipose  a  well  to  be  4  feet  9  inches  diameter,  and  16^  feet 
from  the  bottom  to  the  surface  of  the  water  ;  how  many  gallons 
are  therein  contained  ? 

4.75-  X  i6.5  X  5.875  =  2187.152  gallons. 

Again,  suppose  the  well's  diameter  the  same,  and  its  entire 
depth  35  feet ;  required  the  quantity  in  cubic  yards  of  material 
excavated  in  its  formation. 

4.75^  X  35  X  .02909  =  22.972  cubic  yards. 

A  cylindrical  piece  of  lead  is  required  7^-  inches  diameter,  and 
168  lbs.  in  weight ;  what  must  be  its  length  in  inches  ? 
7.5^  X  .3223  =  18,  and  1G8  -M8  =  9.3  inches. 

Digging  for  Foundations,  tSc. —To  find  the  cubical 
quantity  in  a  trench,  or  an  excavated  area,  the  length,  width, 
and  depth  must  be  multiplied  together.  These  are  usually  given 
in  feet,  and  therefore,  to  reduce  the  amount  into  cubic  yards  it 
must  be  divided  by  27. 

Suppose  a  trench  is  40  feet  long,  3  feet  wide,  and  3  feet  deep, 
required  the  number  of  cubic  feet,  or  yards. 

40  X  3  =  120  X  3  =  360  feet-^27  =  131  yards. 

24  cubic  feet  of  sand,  17  ditto  clay,  18  ditto  earth,  equal  one 
ton. 

1  cubic  yard  of  earth  or  gravel,  before  digging,  will  occupy 
about  1|  cubic  yards  when  dug. 


Measurement  of  Masons'  Work. 

To  masonry  belong  all  sorts  of  stone-work  ;  and  the  measure 
made  use  of  is  a  foot,  either  superficial  or  solid. 

Walls,  columns,  blocks  of  stone  or  marble,  &c.,  are  measured 
by  the  cubic  foot ;  and  pavements,  slabs,  chimney-pieces,  &c., 
by  the  superficial  or  square  foot.  Cubic  or  solid  measure  is 
used  for  the  materials,  and  square  measure  for  the  workmanship. 
In  the  solid  measure,  the  true  length,  breadth,  and  thickness 
are  taken,  and  multiplied  continually  together.  In  the  super- 
ficial, there  must  be  taken  the  length  and  breadth  of  every  part 
of  the  projection,  which  is  seen  without  the  general  upright  face 
of  the  building. 

Example — In  a  chimney-piece,  suppose  the  length  of  the 
mantel  and  slab  each  4  feet  6  inches  ;  breadth  of  both  together 
3  feet  2  inches  ;  length  of  each  jamb  4  feet  4  inches  ;  breadth  of 


30  MRASUREMENT   OF 

both  together  1  foot  9  inches.     Eequired  the  superficial  contents. 

Alls.  21  feet  10  inches. 

4  ft.  6  in.  X  3  ft.  2  in.  =  14  ft.  3  in.  (  oi  f    nn  •     i 
4  "  4  "   X  1  "   9  "   =   7  '•  7  "    H ^  feet  10  inches. 

Hubble  Walls  (nnhewn  stone)  are  commonly  measured  by 
the  perch,  which  is  16.]  feet  lonj,',  1  foot  deep,  and  \\  foot  thick, 
equivalent  to  24|  cubic  feet.  25  cubic  feet  is  sometimes  allowed 
to  tlie  perch,  in  measuring  stone  before  it  is  laid,  and  22  after  it 
is  laid  in  the  wall.  This  species  of  work  is  of  two  kinds,  coursed 
and  uncoursed  ;  in  the  former  the  stones  are  gauged  and  dressed 
by  the  hammer,  and  the  masonry  laid  in  horizontal  courses,  but 
not  necessarily  confined  to  the  same  height.  The  uncoursed 
rubble  wall  is  formed  by  laying  the  stones  in  the  wall  as  they 
come  to  hand,  witliout  any  previous  gauging  or  working. 

27  cubic  feet  of  mortar  require  for  its  preparation,  9  bushels 
of  lime  and  1  cubic  foot  of  sand. 

Lime  and  sand  lessen  about  one-third  in  biilk  when  made  into 
mortar  ;  likewise  cement  and  sand. 

Lime,  or  cement  and  sand,  to  make  mortar,  require  as  much 
water  as  is  equal  to  one-third  of  their  bulk. 

All  sandstones  ought  to  bo  placed  on  their  natural  beds  ;  from 
inattention  to  this  circumstance,  the  stones  olten  sjilit  oft'  at  the 
joints,  and  the  position  of  the  lamina  much  sooner  admits  of  the 
destructive  action  of  air  and  water. 

Tlie  heaviest  stones  are  most  suited  for  docks  and  harbors, 
breakwaters  to  bridges,  Ac. 

Granite  is  the  most  durable  species  of  stone  yet  known  for  the 
purposes  of  building.  It  varies  in  weight  according  to  quality  ; 
the  heaviest  is  the  most  durable. 


Measurement  of  Carpenters'  and  Joiners'  Work. 

To  this  branch  belongs  all  the  wood-work  of  a  liouse,  such  a.s 
flooring,  partitioning',  roofing,  &.G.  Large  and  ])lain  articles  are 
usually  measured  by  the  square  foot  or  yard,  iVc,  Init  enriched 
mouldings,  and  some  other  articles,  are  often  estimated  by 
running  or  lineal  measures,  and  some  things  are  rated  by  the 
piece. 

Joints,  Girders,  and  in  fact  nil  the  parts  of  naked  floor- 
ing, are  measurcid  liy  tlio  cube,  and  their  quantities  are  found  by 
multiplying  the  length  l)y  the  breadth,  and  the  ))r<>duct  by  the 
depth.  The  same  rule  api)li(^s  to  the  UK^asurcmcnt  of  all  the 
timbc'rs  of  a  roof,  and  also  the  framed  timbers  used  in  the  con- 
struction of  j)artitions. 

Flitoring ,  that  is  to  say,  the  boards  wliich  cover  tlio  naked 
flooring,  is  miyisured  by  the  square.  The  dimensions  are  taken 
from  wall  to  wall,  and  tli<!  |)roiluctis  divided  by  100,  wliicli  gives 
the  numlxir  of  s(|uarcs  ;  but  deductions  must  bo  nuuh;  for  stair- 
cases and  chiinneys. 

In  measuring  f)f  joists,  it  is  to  bo  ol)S(!rved,  that  only  one  of 
their  dimensions  is  the  same  with  that  of  the  floor  ;  for  the  other 
exceeds  the  length  of  the  room  by  the  thickness  ot  the  wall,  and 


carpenters'  j!iND  joiners'  work.  31 

one-tliird  of  the  same,  because  each  end  is  lot  into  the  wall  about 
two-thirds  of  its  thickness. 

No  deductions  are  made  for  hearths,  on  account  of  the  ad- 
ditional trouble  and  ■waste  of  materials. 

Partitions  are  measured  from  wall  to  wall  for  one  dimen- 
sion, and  from  floor  to  floor,  as  far  as  they  extend,  for  the  other. 

No  dediiction  is  made  for  door-ways,  on  account  of  the  trouble 
of  framing  them. 

In  maasuring  of  joiners'  work,  the  string  is  made  to  ply  close 
to  every  part  of  the  work  over  which  it  i^asses. 

The  measuring  for  centring  for  cellars  is  found  by  making  a 
string  pass  over  the  surface  of  the  arch  for  the  breadth,  and 
taking  the  length  of  the  cellar  for  the  length  ;  but  in  groin 
centring,  it  is  usual  to  allow  double  measure,  on  account  of 
their  extraordinary  trouble. 

Roofing. — The  length  of  the  house  in  the  inside,  together 
with  two-thirds  of  the  thickness  of  one  gable,  is  to  be  considered 
as  the  length;  and  the  breadth  is  equal  to  double  the  length  of  a 
string  which  is  stretched  from  the  ridge  down  the  rafter,  and 
along  the  eaves-board,  till  it  meets  with  the  tojD  of  the  wall. 

Staircases. — Take  the  breadth  of  all  the  stejis,  by  making  a 
line  ply  close  over  them,  from  the  top  to  the  bottom,  and  multi- 
ply the  length  of  this  line  by  the  length  of  a  step  for  the  whole 
area.  By  the  Isngth  of  a  step  is  meant  the  length  of  the  front 
and  the  returns  at  the  two  ends;  and  by  the  breadth  is  to  be  un- 
derstood the  girth  of  its  two  outer  surfaces,  or  the  tread  and 
riser. 

Balustrade. — Take  the  whole  length  of  the  upper  part  of 
the  handrail,  and  girt  over  its  end  till  it  meets  the  top  of  the 
newel  post,  for  the  length ;  and  twice  the  length  of  the  baluster 
upon  the  landing,  with  the  girth  of  the  handrail,  for  the  breadth. 

Wainscoting. — Take  the  compass  of  the  room  for  the  length; 
and  the  height  from  tha  floor  to  the  ceiling,  making  the  string 
ply  close  into  all  the  mouldings,  for  the  breadth.  Out  of  this 
must  be  made  deductions  for  windows,  doors,  chimneys,  Ac, 
but  workmanship  is  counted  for  the  whole,  on  account  of  the  ex- 
traordinary trouble. 

Doors. — It  is  usual  to  allow  for  their  thickness,  by  adding  it 
to  both  dimensions  of  length  and  breadth,  and  then  to  multiply 
them  together  for  the  area.  If  the  door  be  panelled  on  both  sides, 
take  double  its  measure  for  the  workmanship;  but  if  the  one  side 
only  be  panelled,  take  the  area  and  its  half  for  the  workmanship. 
For  the  surrounding  architrave,  gird  it  about  the  outer- 
most parts  for  its  length;  and  measure  over  it,  as  far  as  it  can  be 
seen  when  the  door  is  open,  for  the  breadth. 

Windo IV- Shutters,  liases,  tSc,  are  measured  in  the 
same  manner. 

In  the  measuring  of  roofing  for  workmanship  alone,  holes  for 
chimney-shafts  and  skylights  are  generally  deducted.  But  in 
measuring  for  work  and  materials,  they  commonly  measure  in  all 
skylights,  lutheran-lights,  and  holes  for  the  chimney-shafts,  on 
account  of  their  trouble  and  waste  of  materials. 


32 


MEASUREMENT   OF   SLATERS'  WORK. 


The  doors  and  shutters,  being  worked  on  both  sides,  arc  reck' 
oned  work  and  half  work. 

Jleinlock  and  Pine  Shingles  are  generally  18  inches  long 
and  of  the  average  widtli  of  4  inches.  When  nailed  to  the  roof, 
6  inches  are  generally  left  out  to  the  weather,  and  G  shingles  are 
therefore  required  to  a  square  foot.  Cedar  and  Cypress 
Shingles  are  generally  2U  inches  long  and  0  inches  wide,  and 
therefore  a  less  number  are  required  lor  a  "square."  On  account 
of  waste  and  defects,  1,000  shingles  should  be  allowed  to  a  square. 

Two  4-penny  nails  are  allowed  to  each  shingle,  equal  to  1,200 
to  a  square. 

The  weight  of  a  square  of  partitioning  may  be  estimated  at 
from  1,;jOO  to  2,000  lbs.;  a  square  of  single-joisted  flooring,  at 
from  1,200  to  2,000  lbs.;  a  square  of  framed  flooring,  at  from 
2,700  to  4,500  lbs.;  a  square  of  deafening,  at  about  1,500  lbs. 
100  superficial  feet  make  one  square  of  boarding,  flooring,  &c. 

In  selecting  Timber,  avoid  spongy  heart,  i)orous  grain,  and 
dead  knots;  choose  the  brightest  in  color,  and  where  the  strong 
red  grain  appears  to  rise  on  the  surface. 


Number  of  American  Iron  Machine-Cut  Nails  in  a 
Poujid  (by  count'. 


Size. 

Number 

Size. 

Number 

Size. 

Number. 

3-penny, 

4  " 

5  " 

408 
275 
227 

fi-peiiny, 
8      '• 
10      " 

15G 

100 

66 

12-penny, 
20      " 
30      " 

52 
32 

25 

Measurement  of  Slaters'  Work. 

In  these  articles,  the  contents  of  a  roof  aro  found  by  multiply- 
ing the  length  of  the  ridge  by  the  girth  over  from  eaves  to  eaves; 
making  allowance  in  this  girth  for  the  double  row  of  slates  at  the 
bottom,  or  for  how  much  one  row  of  slates  is  laid  over  another. 
When  the  roof  is  of  a  truf  pitch,  that  is,  forming  a  right  angle  at 
top,  then  till!  liroadth  of  the  building,  with  its  lialf  added,  is  tho 
girth  over  both  sides.  In  angles  formed  in  a  roof,  running  from 
the  ridge  to  the  caves,  when  the  angle  l)cnds  inward,  it  is  called 
(V  valley;  but  wlien  outward,  it  is  culled  a  hi]).  It  is  not  usual 
tn  iiiaki!  deductions  for  cliimney-sliufls,  skylights,  or  other 
oiJenings, 


SLATES, 
Slates. 

iFroinihe  Quarries  of  Builand  County.  Vermontli 


33 


3  inch  Cover. 

2  inch  Cover. 

3  inch  C(Jver. 

2  inch  Cover. 

No  of  folates 

No.  of  Slates 

No.  of  Slates 

No.  of  Slates 

Sizes. 

to  the  square 

to  the  square 

Sizes. 

to  the  square 

to  the  square 

or  100  feet. 

or  100  feet. 

18  by  11 

or  100  feet. 

or  ICO  feet. 

24  by  16 

86 

84 

1741 

163| 

24  by  14 

98 

93^ 

18  by  It' 

192 

180 

24  by  12 

114 

109 

18  by    9 

213 

200 

22  by  14 

108 

1021 

16  by  12 

184 

17U 

22  by  12 

126 

120 

16  by  10 

221  J- 

205a 

22  by  10 

152 

144 

16  by    9 

246 

228.^ 

20  by  14 

129 

114^ 

16  by    8 

277 

257" 

20  by  12 

143 

1331 

14  by  10 

262 

240 

20  by  11 

146 

145.^ 

14  by    9 

293 

266i 

20  by  10 

1691- 

160 

14  by    8 

327 

300 

18  by  12 

160 

150 

14  by    7 

374 

343 

Each  Slate  is  3  inches  bond  or  cover.  The  rule  for  measuring 
Slating  is,  to  add  one  foot  for  all  hips  and  valleys.  No  deduction 
is  made  for  lutheran-lights,  skylights,  or  chimneys,  except  they 
are  of  unusual  size;  then  one-half  is  deducted. 


Imported  Slates. 


Names  of  Slates. 

Sizes. 

No.  of  Superficial 
Feet  each  M  of 
1200  will  cover. 

Weight  of 

each  M  of  1200 

Slates. 

Duchesses 

Marchionesses    

Countesses 

Viscountesses 

Ladies 

Inches.    Inches. 
24    by    12 
22     "     12 
20     "     10 
18     "     10 
16     "     10 
16     "       8 
14     "       8 

12  "       8 
14     "     12 

13  "     10 

12  "     10 

13  "       7 
11     "       7 

5  ft  by  2  1-2  ft. 
5  feet  by  3  feet 

1100 

1000 
750 

666   2-3 
5S3    1-3 
466   2-3 
400 

333   1-3 
6('0 

458    1  3 
416  2-3 
320   5-6 
262   1-2 

60               cwt. 

55 

40 

36 

31 

do 

25 

do 

do 

Plantations 

22 

18  1-2 
33 

do 

do 

Doubles  

25 
23 
17  1-2 

do.      small 

School    Slates   for 
Blackboards 

14  1-2 

34    plasterers',  pavers',  and  painters'  work. 

Measurement  of  Plasterers'  Work. 

Plasterers'  work  is  of  two  kinds,  namely,  ceiling,  wliicli  is 
plastering  upon  laths;  and  rendering,  which  is  plastering  upon 
walls,  which  are  measured  separately. 

The  contents  are  estimated  either  by  the  foot  or  yard,  or  square 
of  lUO  feet.  Enriched  mouldings,  S:c.,  are  rated  by  running  or 
lineal  measure.     One  foot  extra  is  allowed  for  each  mitre. 

One  half  of  the  openings,  windows,  doors,  &c.,  allowed  to 
compensate  for  trouble  of  finishing  returns  at  top  and  sides. 

Cornices  and  mouldings,  if  12  inches  or  more  in  girt,  are  some- 
times estimated  by  the  square  foot;  if  less  than  12  inches,  they 
are  usually  measured  by  the  lineal  foot. 
1  bushel  of  cement  will  cover  1  1-7  sq.  yds.  at  1  in.  in  thickness. 

I        >'  <t  11  11  II  2  11 

'  ^5  4 

1    "  "  1'        21-         "  i         " 

1  bushel  of  cement  and  1  of  sand  will  cover  ?^  sq.  yds,  at  1  inch 

in  thickness. 
1  bushel  of  cement  and  1  of  sand  will  cover  3  sq.  yds.  at  ^  inch 

in  thickness. 
1  bushel  of  cement  and  1  of  sand  will  cover  4.\  sq.  yds.  at  ^  inch 

in  thickness. 
1  bushel  of  cement  and  2  of  sand  will  cover  3J  sq.  yds.  at  1  inch 

in  thickness. 
1  bushel  of  cement  and  2  of  sand  will  cover  4J  sq.  yds.  at  ^  inch 

in  thickness. 
1  bushel  of  cement  and  2  of  sand  will  cover  6J  sq.  yds.  at  J  inch 

in  thickness. 
1  cwt.  of  mastic  and  1  gallon  of  oil  will  cover  1 J  yards  at  I,  or  2J 

at  I  inch. 
1  cubic  yard  of  lime,  2  yards  of  road  or  drift  sand,  and  3  bush- 
els of  hair  will  cover  7.'3  yards  of  render  and  set  on  brick,  and  70 
yards  on  lath,  or  65  yards  plaster,  or  render,  2  coats  and  set  on 
brick,  and  GO  j^ards  on  lath;  floated  work  will  require  about  the 
same  as  2  coats  and  set. 

Laths  are  1\-  to  IJ  inches  by  4  feet  in  lenLjth,  and  are  usually 
set  \  of  an  inch  apart.  A  bundle  contains  lO'J.  1  bundle  of 
laths  and  COO  nails  will  cover  about  4  ^  yards. 


Measurement  of  Pavers'  Work. 
Pavers'  work  is  done  liy  the-  sijuare  yard.     And  the  contents  are 
found  Ijy  nuiltiplying  the  length  by  the  breadth.     Grading  for 
jjaving  is  charged  by  the  day. 


Measurement  of  Painters'  Work. 

Painters'  work  is  computed  in  scjuare  yards.  ICvrry  part  is 
measured  where  the  color  lies;  the  measuring  lino  is  forced  into 
all  the  mouldings  and  corners. 

Cornices,  moaidings,  narrow  skirtings,  reveals  to  doors  and 
win<lo\vs,  and  gemrally  all  work  not  more  than  nine  inches  wide, 
are  valued  by  their  length.  .Sasli-frami;s  are  charged  so  much 
each  according  to  their  size,  and  the  K(inares  so  much  a  do^en. 
Mouldings,  cut  in,  are  cliarged  by  the  foot  run,  and  the  workman 


GLAZIERS    WORK. 


35 


always  receives  an  extra  price  for  party-colors.  "Writing  is 
charged  bj'  the  inch,  and  the  price  given  is  regulated  by  the  skill 
and  manner  in  which  the  work  is  executed;  the  same  is  true  of 
imitations  and  marbling.  The  price  of  painting  varies  exceed- 
ingly, some  colors  being  more  expensive  and  requiring  much 
more  labor  than  others.  In  measuring  open  railing,  it  is  cus- 
tomary to  take  it  as  flat  work,  which  pays  for  the  extra  labor;  and 
as  the  rails  are  painted  on  all  sides,  the  two  surfaces  are  taken. 
It  is  customary  to  allow  all  edges  and  sinkings. 


Measurement  of  Glaziers'  Work. 
Glaziers'  work  is  sometimes  measured  by  the  square  foot, 
sometimes  by  the  piece,  or  at  so  much  per  light;  except  where 
the  glass  is  set  in  metallic  frames,  when  the  charge  is  by  the  foot. 
In  estimating  by  the  square  foot  it  is  customarj'  to  include  the 
whole  sash.  Circular  or  oval  windows  are  measured  as  if  they 
were  square. 


Table  Showing  the  Size  and  Number  of  Lights  to 
the  100  Square  Feet. 


Size. 

Lights 

Size. 

Lights 

Size. 

Lights 

Size. 

Lights 

6  by  8 

300 

12  by  14 

86 

14  by  22 

47 

20  by  20 

36 

7  by  9 

229 

12  by  15 

80 

14  by  24 

43 

20  bv  22 

33 

8  by  10 

1«0 

12  bv  16 

75 

15  by  15 

64 

20  by  24 

30 

8  by  11 

164 

12  b>  17 

71 

15  by  16 

60 

20  by  25 

29 

8  by  12 

150 

12  by  18 

67 

15  by  18 

53 

20  bv  26 

28 

9  by  10 

160 

12  by  19 

63 

15  by  20 

48 

20  by  28 

26 

9  by  11 

146 

12  by  20 

60 

15  by  21 

46 

21  by  27 

25 

9  by  12 

133 

12  b'y  21 

57 

15  by  22 

44 

22  by  24 

27 

9  by  13 

123 

12  by  22 

55 

15  by  24 

40 

22  by  26 

25 

9  by  14 

114 

12  by  23 

52 

16  by  16 

56 

22  by  28 

23 

9  by  16 

100 

12  by  2t 

50 

16  by  17 

53 

24  by  28 

21 

10  by  10 

144 

13  bv  14 

79 

16  by  18 

50 

24  by  30 

20 

10  by  12 

120 

13  by  15 

74 

16  by  20 

45 

24  by  32 

19 

10  by  13 

111 

13  by  16 

69 

16  by  21 

43 

25  by  30 

19 

10  by  14 

103 

13  by  17 

65 

16  by  22 

41 

26  by  36 

15 

10  by  15 

96 

13  by  18 

61 

16  by  24 

38 

28  by  34 

15 

10  by  16 

9J 

13  by  19 

58 

17  by  17 

50 

30  by  40 

12 

10  by  17 

85 

13  by  20 

55 

17  by  18 

47 

31  bv  36 

13 

10  by  18 

80 

13  by  21 

53 

17  by  20 

42 

31  bV40 

12 

11  by  11 

119 

13  by  22 

50 

17  by  22 

38 

31  b'y  42 

12 

11  by  12 

1U9 

13  by  24 

46 

17  by  24 

35 

32  by  42 

10 

11  by  13 

101 

14  bv  14 

7i 

18  by  18 

44 

32  by  44 

10 

1 1  by  14 

94 

14  by  15 

68 

18  by  20 

40 

33  by  43 

10 

11  by  15 

87 

14  by  16 

64 

18  by  22 

36 

34  by  46 

9 

11  by  16 

82 

14  by  17 

60 

18  by  24 

33 

30  by  52 

9 

11  by  17 

77 

14  by  18 

57 

19  by  19 

40 

32  by  56 

8 

11  by  18 

73 

14  by  19 

54 

19  by  20 

38 

33  by  56 

8 

12  by  12 

100 

14  by  20 

51 

19  by  22 

3t 

36  by  58 

7 

12  bv  13 

92 

14  by  21 

49 

19  by  24 

32 

38  by  58 

7 

3G  GAUGING   OP   CASKS. 

Measurement  of  Plumbers'  Work. 

Plumbers'  work  is  rated  at  so  much  a  pound,  or  else  by  the 
hundred-weight  of  112  pounds.      Sheet   lead,  used  in  roofin" 
guttering,  &c.,  is  from  7  to  12  lbs.  to  the  square  foot;  and  a  pipe 
ot  an  inch  bore  is  commonly  from  G  to  13  lbs.  to  the  yard  in 
length.     [See  Table,  "  Weight  of  Lead  Pipe  per  Foot."] 


OAUGING-  OF  CASKS. 


In  taking  the  dimensions  of  a  Cask,  it  must  be  carefully  ob- 
served :  1st,  That  the  buug-holo  be  in  the  middle  of  the  cask  • 
2d,  That  the  bung-stave,  ixnd  the  stave  opposite  to  the  bun^-hole' 
are  both  regular  and  even  within  ;  3d,  That  the  heads'of  the 
Cask  are  e.iual,  and  truly  circular  ;  if  so,  the  distance  between 
the  inside  of  tUe  chime  to  the  outside  of  the  opposite  stave  will 
be  the  head-diameter  within  the  cask,  very  near. 

Rule  —Take,  in  inches,  the  viside  diameters  of  a  Cask  at  the 
head  and  the  bung,  ami  also  the  length  ;  subtract  the  head-di- 
ameter from  the  bung-diameter,  and  note  the  difference. 

If  the  measure  of  the  Cask  is  taken  outside,  with  calipers, 
from  head  to  head,  then  a  deduction  must  be  made  of  from  1  to 
2  inches  for  the  thickness  of  the  heads,  according  to  the  size  of 
the  Cask.  ^ 

1.  If  (he  slaves  of  the  Cask,  between  Uie  bung  and  the  heail,  are 
consitlerahli/  riirved  (the  shape  of  a  pipe\  multiply  the 
difference  between  the  bung  and  head,  by  .7. 

2.  If  (he  .staves  be  of  a  nicdiinn  viirre  (the  shape  of  a  mo- 
lasses hogshead),  multiply  the  difference  by  .05. 

3.  If  (he  staves  r II  rre  vvvii  /*7/^^le.ss  than  a  molasses  hogs- 
head), multiply  the  difference  by  .G. 

4.  If  the  slaves  are  iirarlf/  stiui'njht  (almost  a  cylinder), 
multiply  the  difference  liy  .55. 

5.  Add  the  i)roiluct,  in  each  case,  to  tlie  head-diameter  ;  the 
sum  will  be  a  mean  diameter,  and  tlius  the  Cask  is  reduced  U^  a 
cylinder. 

0.  Multii)ly  the  inran  diameter  by  itself,  and  then  by  the 
length,  and  multiply,  if  fnr  wiue-galloiis,  by  .(1031.  The  difference 
of  dividing  by  2'.il  (the  usual  luetliod*.  and  multiplying  liy  .()o:{4 
(t!io  most  expeditious  method  >,  is  less  than  oUUths  of  a  gaUon  in 
It  0  gallons. 

ExAMi'i.K.— Supj)nsing  the  head-diametor  of  a  Cask  to  be  21 
inclus,  tho  bung-diameter  32  inclies,  and  the  length  of  Cask  40 
inchcH,  what  are  tho  contents  in  wine  gallons? 


gaugixg  of  casks. 


37 


Bung-Diameter, 
Head-Diameter, 

Difference, 
Multiplier, 

First 

32 

24 

8 
.7 

5.6 
21 

29.6 
29.6 

variety. 

Brought 
Length, 

up,  876.16 
40 

35046.40 
.0034 

Head-Diam., 

14018560 
10513920 

multiply 

by 

119.157760 

Scpiare,     876.16 


Ans.   119  galls.  1  pint. 


To  obtain  the  content.?  of  a  similar  Cask  in  ale  gallons,  multi- 
ply 35046.40  by  .032785,  and  we  get  97.6042  (or  97  gallons  5 
pintsj. 


Gauging  of  Casks  in  Imperial  (British)  gallons,  and. 
also  in  United.  States  gallons. 

Having  ascertained  the  vnrietif  of  the  Cask,  and  its  interior  di- 
mensions, the  following  Table  will  facilitate  the  calculation  of  its 
capacity. 

Table  of  the  Capacities  of  Casks,  whose  Bung-Di- 
ameters and  Lengths  are  1  or  Unity. 


H. 

Ist  Var.  2d  Var 

3d  Var.  4th  Var. 

H. 

.76 

1st  Var. 

2d  Var. 

3d  Var.  4th  Var. 

.50 

0021244  .0020300'  0017T04  .nn]6'.23 

0024337 

.0021120 

.0022343  .0022071 

.51 

.0021340  0020433 

.0017847 

.001B713 

.77 

.0024482 

.0024282 

.(022560  .0022310 

.52 

.0021437 

.00205 >7 

.0017993 

.0016905 

.78 

.0024628 

.0024445 

.0022780  .0022551 

.53 

.0021036 

.0020702 

.0018141 

.(017098 

.79 

0024777 

.0024^10 

.00230021.0022794 

.54 

.0021637 

.0020838 

001S293 

0017294 

.80  .0024927 

.0024776 

.0023227 

.0023038 

.55 

.0021740 

.0020975 

.0018*47 

.0017491 

.81 

.0025079 

.0024942 

.0023455 

.0023285 

..56 

.0021845 

.0021114 

.00I8n04 

.0017090 

.82 

0025233 

.0025110 

.0023686 

.0023533 

.57 

.0021951 

.0021253 

.0018764 

.0017891 

.83 

.0025388 

.0U25279 

.0023920 

.0023783 

.58 

.0022060 

.0021394;. 0018927 

.0018094 

.84 

.002554fi 

.0023449 

.00241.56 

.0024033 

.59 

.0022170 

.0U21.i3'i 

.0019U93 

0018299 

.85 

.0025706 

.0025621 

.0024396 

.1024289 

.60 

.0022283 

.0021679 

0019201 

.011)8506 

.86 

.0  125867 

.0023793 

.0024638 

.0024545 

.61 

.0022397 

.0021823 

0019433 

0018715 

.87 

.0026030 

0025967 

0024883 

.1024803 

.62 

.0022513 

.0021968 

.0019007 

.001892.5 

.88 

.0026191 

0026141 

.0025131 

.0025003 

.63 

. 0022-131 

.0022114 

.0019784 

.0019138 

.89 

.00263  ;3 

.0026317 

.0025381 

.0025324 

.64 

.0022751 

.0022202 

.0019964 

.0(ji;i352 

.90 

.002;;532 

.0026494 

.0025635 

.00255S8 

.65 

.0022873 

.0022410 

.0020147 

.0019.568 

.91 

.0026703 

.002  W72  .0023891 

.0025853 

.66 

.0022997 

0022560 

.0020332 

.0019786 

.92 

.0026875 

.0026851  .0026150 

■0026120 

.67 

.0023122 

.0022711 

.0020521 

.00-:  0006 

.93 

.0027050 

.0027032  .0026412 

•0026389 

.68 

.0023250 

.0022803 

.0020712 

.0020228 

.94 

.0027227 

.0027213  .0026677 

•0026660 

.69 

.UO 23379 

.0023010 

.0020906 

.0020452 

.95 

.0027403 

.00273961.0026945 

0026933 

.70 

.0023.'510 

.002'il70 

.0021103 

.r020678 

.96 

0027585 

.0027579 

.0027215 

.0027208 

.71 

.002364i 

.0023326 

.0021302 

.0('20905 

.97 

.00277-^8 

.0027764 

.0027489 

■0027481 

.72 

002377S 

.0023482 

.0021505 

.0021135 

.98 

.0027952 

.0027950 

0027765 

•0027703 

.73 

.002391.T 

.0023640 

.0021710 

.0021366 

.99 

.0028138 

.0028137 

0028044 

.0028043 

.74 

.0024054  .0023799 

.0021918 

.0021'99 

1.00 

.0028320 

.0028326 

•  0028326  .0028326 

.75 

. 002419.il. 00239.=i9 

.0022129 

.0021834 

38  GAUGING   OF    CASKS. 

Divide  the  bead  by  tbe  bting-diameter,  and  opposite  tbe  quo- 
tient in  tbe  column  H,  and  under  its  proper  variety,  is  tbe  tabu- 
lar number  for  unity.  Multiply  tbe  tabular  mimber  by  tbe 
square  of  tbe  bung-diameter  of  tbe  given  Cask,  and  by  its  lengtb, 
tbe  product  equals  its  caimcity  in  Imi^erial  gallons. 

Required  tbe  number  of  gallons  in  a  Cask  {1st  variety),  24 
incbes  bead-diameter,  32  bung-diameter,  and  4  J  incbes  in 
length. 

32)  24.0  (.75  see  Table  for  tabular  No. 

.0024195  tabular  No.  for  unity. 
32  X  32       is  1024  square  of  bung-diam. 


96783 
48390 
24195 


2.4775G80 

40  incbes  long. 


99.1027200  Imperial  gallons. 
1.2 


1982054400 
9910:::72l)0 


118.9232G4L0  United  States  gallons. 

Note. — Multijilying  Imperial  gallons  by  one  and  two-tentbs 
(1.2)  will  convert  tbcm  into  U.  S.  gallons  ;  and  U.  S.  gallons, 
multiplied  by  .833,  equal  Imperial  gallons. 


To  Ullage,  or  find  the  Contents  in  Gallons  of  a 
Cask  partly  filled. 

Tc  find  the  contents  of  tbe  occupied  part  of  a  lying  cask  in , 
gallon.s. 

Utile. — Divide  tbe  dt'])tli  of  the  li(]uid,  or  wot  incdics,  by  tbe 
bung-diamet<;r,  and  if  tlie  (piotient  is  under  .5,  dedu(^t  from  tlio 
(pii)ticnt  one-fourlli  of  wbiit  it  is  less  than  .5,  and  multii>ly  tbe  re- 
n.aiiidir  by  tbe  wbob'  caiiacity  of  tlic  cask;  tliis  ])ro<lnct  will  b(» 
till-  niiiiibcr  of  gitlldiis  in  tlu!  cask.  Ibit  if  the  (|ii(iti(iit  exceeds 
.5,  add  <»ic-j<>nrth  of  tbat  excess  to  tlic  quotient,  and  mulli|>ly  tli<! 
sum  by  tlie  wliole  capacity  of  tbe  cask;  this  product  will  be  tbe 
number  f>f  gallons. 

Example  1.  —  Suppose  tbe  bung-diameter  of  a  cask,  on  its  bilge, 
is  32  inches,  and  tbe  whole  (contents  of  tbe  cask   118.80  U.  S. 
standard  gulloiis;  rerjuired  tbe  ullag(!  of  15  wet  inches. 
32 )  15. 00  i .  \  (1875      .5     . 4(iS75  -  -  .031 25  —  4  tr^  0078 1 25      .  A  0875  - 
.0078125  =  .4609375  X  1 1 8. 80  =  54. 759375  U.  S.  gallons. 


PLOUGHING.  39 

Example  2. — Eequired  the  ullage  of  17  wet  inches  in  a  cask  of 
the  above  capacity. 

32)  i7.U0  (.53125 ^.5  =  .03125-^'!  =  . 0078125 +  . 53125  =  .5390G25 
X  118.80  =  G1.040G25  U.  S.  gallons. 

Tkoof.— 04.010625  +  51.759375  =  118.80  gallons. 

To  find  the  ullage  of  a  filled  part  of  a  standing  cask  in  gallons. 

RuiiE. — Divide  the  depth  of  the  liquid,  or  wet  inches,  by  the 
length  of  the  cask;  then,  if  the  qiiotient  is  less  than  5,  deduct 
from  the  quotient  one-tenik  of  what  it  is  less  than  .5,  and  multiply 
the  remainder  by  the  whole  cai^acity  of  the  cask;  this  product 
will  be  the  number  of  gallons.  But  if  the  quotient  exceeds  .5, 
add  one-tenth  of  that  excess  lo  the  quotient,  and  multiply  the  sum 
by  the  whole  capacity  of  the  cask;  this  product  will  be  the  ullage, 
or  contents  in  U.  S.  standard  gallons. 

Example. — Sujipose  a  cask,  40  inches  in  length,  and  the  capa- 
city 118.80  gallons,  as  above;  required  the  ullage  of  21  wet  inches. 

40)  21.000  (525  — .5  =  . r25-^  10  =  .0025 +  .525  =  .5275X118.80 
=  62.667  U.  S.  gallons. 

Note. — Formerlj^  the  British  wine  and  ale  gallon  measures 
were  similar  to  those  now  used  in  the  United  htates  and  British 
Colonies. 

The  following  Tables  exhibit  the  comparative  value  between 
the  United  States  and  the  present  British  measures: 

U.  S.  measure  for  British  (Im.)  measure. 

wine,  spirits,  &c.  galls,   qts.  pts.  gills. 

42  gallons  =  1  tierce         =34        3        1        3 
63  =1  hogshead  =52        1        1        3 

126  =1  pipe  =104        3        1        3 

252  =ltun  =2t9        3        12 

U.  S.  measure  for  British  (Im. )  measure. 

ale  and  beer.  galls 

9  gallons  =  1  firkin         =      9 

36  =  1  V)arrel        =    36 

54  =  1  hogshead  =    54 

108  =  1  butt  =  109 

To  convert  Imperial  gallons  into  United  States  wine  gallons, 
multiply  the  Imperial  by  1.2.  To  convert  U.  S.  gallons  into  Im- 
perial, multiply  the  U.  S.  wine  gallons  by  .833. 

Sixty  U.  S.  ale  gallons  equal  61  Imperial  gallons,  therefore  to 
convert  one  into  the  other  add  or  deduct  1-GOth. 


qts. 

pts. 

gills. 

0 

1 

1 

2 

0 

3 

3 

1 

1 

3 

0 

3 

Ploughing. 

Table  showing  the  distance  travelled  by  a  horse  in  ploughing  an 
acre  of  land;  also  the  quantity  of  land  worked  in  a  day,  at  the 
rat?  of  16  and  18  miles  per  day  of  9  hours. 


40 


PLOUGHING. 


B'dthof 
furrow 

Space  travel- 
ed in  plough- 

Extent plough'd 
per  day. 

B'dthof 
furrow 

Space  travel- 
ed in  plough- 

Extent plough'd 
per  day. 

slice. 

ing  an  acre 

slice. 

ing  an  acre. 

Inches. 

Miles. 

18  miles 

IG  miles 

Inches. 
14 

Miles. 

18  miles 

16  miles 

7 

14  1-2 

1  1-4 

1  1-8 

7 

2  1-2 

2  1-4 

8 

12  1-2 

11-2 

1  1-4 

15 

6  1-2 

2  3-4 

2  2-5 

9 

11 

13-5 

1  1-2 

IG 

(5  1-0 

2  9-10 

2  3-5 

10 

9  9-10 

14-5 

13-5 

17 

5  3-4 

3  1-10 

2  3-4 

11 

9 

2 

13-4 

18 

5  1-2 

3  1-4 

2  9-10 

12 

8  1-4 

2  1-5 

1  9-10 

19 

5  1-4 

3  1-2 

3  1-10 

13 

7  1-2 

2  1-3 

2  1-10, 

20 

4  9-10 

3  3-5 

3  1-4 

Planting. 

Table  s^-iowing  the  number  of  plants  required  for  one  acre  of 
land,  from  one  foot  to  twenty-one  feet  di.stance  from  plant  to 
plant. 


Feet      Kg  of    Feet      No.  of 

Feet 

1 
No.  of    Feet 

No  of 

Feet 

No.  of 

distance,  hills,  distance,  hi  Is. 

1       • 

distance 

hiUs. 

distance 

hills. 

distance 

hills. 

1          43,560 

4         2,722 

7 

889 

10 

436 

17 

151 

li       19,360 

4,V        2,151 

7^ 

775 

lOh 

361 

18 

135 

2         10,890 

5         1,742 

8 

680 

12 

3!  12 

20 

108 

2\         6,969 

5  A        1,440 

Si 

602 

14 

223 

21 

99 

3           4,840 

(;          1,210 

9 

538 

15 

19J 

25 

C9 

3i         3,556 

6.^        1,031 

9-1 

482 

16 

171 

30 

48 

Weight  of  a  Cord  of  Wood. 

Table  of  the  weight  of  a  cord  of  difl'erent  kinds  of  dry  wood,  and 
the  comparative  value  jjer  cord. 

A  Cord  of  Hiflvorv 4469  pounds Carbon 100 

Maple' 2863        "        "       54 

White  IJireh 2:i69        "       "  ....   48 

"       Bcceh 3236        "        "       65 

"  "       A.sli 3150        "        "       77 

ritch  I'inc 19.14        "       "       43 

Willi"  I'inc 1H6H        "        "       42 

"  Loiiibanh  Poplar,  1774        "        "       40 

White  Uak   3H21         "        "       81 

Yellow  Ouk 2!I19        •'        "       60 

Red  Ouk 3254       "       "      G9 


Note. — Nearly  onr-half  "f  the  weight  of  a  growing  oak-tree 
consists  of  sap.  Ordinary  dry  wood  contains  about  one-fourth 
of  its  weight  in  water, 


IXTESEST    RULES,  41 


Charcoal. 

Oak,  maple,  beech,  and  cliestnut  make  the  best  quality.  Be- 
tween 15  and  17  per  cent,  of  coal  can  be  obtained  when  the  wood 
is  properly  burned.  A  bushel  of  coal  from  hard  wood  weighs  be- 
tween 29  and  31  lbs  ,  and  from  pine  between  28  and  30  lbs. 


Wonders  of  the  American  Continent. 

The  greatest  cataract  in  the  world  is  the  Falls  of  Niagara,  where 
the  water  from  the  great  upper  lakes  forms  a  river  three-fourths 
of  a  mile  in  width,  and  then,  being  siiddenly  contracted,  plunges 
over  rocks  in  two  cohimns  to  the  depth  of  175  feet.  The  greatest 
cave  in  the  world  is  the  Mammoth  Cave  of  Kentucky,  where  any- 
one can  make  a  voyage  on  the  waters  of  a  subterranean  river, 
aud  catch  lish  without  eyes.  The  greatest  river  in  the  world  is 
the  Mississippi,  4,00U  miles  long.  The  largest  valley  in  the  world 
is  the  valley  of  the  Mississippi.  It  contains  5, 000,  (JO  J  square  miles, 
and  is  one  of  the  most  fertile  regions  of  the  globe.  The  greatest 
city  park'  in  the  world  is  in  Philadelphia.  It  contains  2,700 
acres.  The  greatest  grain  port  in  the  world  is  Chicago.  The 
largest  lake  in  the  world  is  Lake  Superior,  which  is  truly  an  in- 
land sea,  being  430  miles  long  and  1,0 JO  feet  deep.  The  longest 
railroad  at  present  is  the  Pacific  Railroad,  over  3,000  miles  in 
length.  The  greatest  mass  of  solid  iron  in  the  world  is  the  Pilot 
Knob  of  Missouri.  It  is  250  feet  high  and  two  miles  in  circuit. 
The  best  specimen  of  Grecian  architecture  in  the  world  is  the 
Girard  College  for  Orphans,  Philadelphia.  The  largest  aqueduct 
in  the  world  is  the  Croton  Aquediict.  New  York.  Its  lengtli  is 
40,}  miles,  and  it  cost  S12,500,(i00.  The  largest  deposits  of  an- 
thracite coal  in  the  world  are  in  Pennsylvania,  the  mines  of  which 
supply  the  market  with  millions  of  tons  annually,  and  appear  to 
be  inexhaustible. 


Excellent  Interest  Rules. 

For  finding  the  interest  on  any  principal  for  any  number  of 
days.  The  answer  in  each  case  being  in  cents,  sejiarate  the  two 
right-hand  figures  of  the  answer  to  express  it  in  dollai-s  and  cents. 

Five  per  cent  — Mu]tix)ly  bv  the  number  of  days,  and  divide 
by  72. 

Six  per  cent. — Multiply  by  the  number  of  days,  separate  the 
right-hand  figure,  and  divide  by  six. 

Eight  per  cent. — Multiply  by  the  number  of  days,  and  divide 
by  45. 

Nine  per  cent. — Multiply  by  the  number  of  days,  separate  the 
right-hand  figure,  and  divide  by  4. 

Ten  per  cent. — Multiply  by  the  number  of  days,  and  divide 
by  35. 


42  BELTING. 

Twelve  per  cent. — Mu'.tiplj'  by  the  mimber  of  clays,  separate 
the  right-hand  figure,  and  divide  by  3. 

Fifteen  jjer  cent.  — Multiply  by  the  number  of  days  and  divide 
by  24. 

'  Eighteen  per  cent. — Multiply  by  the  number  of  days,  separate 
the  right-hand  figure,  an<l  divide  by  2. 

Twent}'  per  cent. — Multiply  by  the  number  of  davs,  and  divide 
by  18. 


BELTING. 

While  the  use  of  belts  for  the  transmission  of  iiower  is  not  an 
American  invention,  the  numerous  improvements  made  in  this 
country  have  caused  it  to  be  known  in  Europe  as  the  A^neri- 
can  system.  In  Europe  the  greater  part  of  the  power  is  trans- 
mitted by  cog-wheels,  but  in  this  country  liU  jjer  cent,  is  trans- 
mitted by  belting.  The  latter  is  used  everywhere,  from  the  sew- 
ing-machine to  the  000  horse-power  engine. 

Jirlts  can  be  run  in  any  way,  at  any  angle,  of  any  length,  and 
at  any  speed,  and  can  be  j)ut  up  bj'  any  (me  of  ordinary  skill. 
They  can  IxMuade  of  any  flexible  material  leather,  rubber,  gutta- 
percha, or  cloth  ;  yet  while  so  handy  and  so  popular,  they  have 
one  fault,  they  are  not  positive.  If  the  motor  makes  a  certain 
number  of  revolutions,  a  portion  of  them  art!  lost  with  every  belt 
used.  This  is  the  only  fault  of  the  system.  It  is  noiseless, 
yielding,  and  regular,  but,  unlike  cog-wheels,  it  is  not  positive. 
The  number  of  revolutions  that  an;  lost  may,  and  do,  vary  con- 
tinually by  changes  f)f  the  load,  or  the  atmosphere. 

Jiclts  (Icrire  their  /Knccr  to  transmit  motion  from  the 
friction  between  the  surface  of  the  belt  and  the  ]>ulley,  and  from 
nothing  else,  and  arc  governed  by  the  same  laws  as  in  friction 
between  tlat  surfaces.  The  friction  increases  regularly  with  the 
pressure.  The  great  dift'eren(Mi  often  observed  in  tlie  friction  ot 
Ix'lts  is  due  simply  to  their  elasticity  of  surface;  that  is,  the  moi-e 
elastic  tlic  surface,  tlie  greater  i\n'  friction. 

///  tiihimj  jtonur  from  iny  sounu;  of  motion  there  are  two 
j)oints  wliicli  control  us;  all  the  others  we  can  control  and  modify 
to  a  certain  extent.  Ordinary  Ix^lts  will  sustain  safely  u  working 
tension  of  1.')  (lounds  i»er  inch  in  width.  Tlie  rul(!  to  determine 
th((  width  of  l)clt  and  si/e  of  ))ulley  recpiired  to  transmit  a  giv<'n 
liorse-power  is  ciisily  found;  since  a  li()rsc-])ower  is:!;!,(l(l()  iiounds, 
ruJHi'd  one  foot  higli  ])cr  minute,  we  must  a<ljust  the  widtli  and 
velocity  of  belts  so  as  to  etf(!ct  thi!  recjuircd  result.  Tliu.s.  if 
tlie  l)elt  moves  with  tlie  velocity  of  T.V.\  ft^et  per  minute,  a  belt  five 
inches  wide  will  transmit  five  liorse-power,  ])rovid(!d  tiie  eftective 
tension  is  •l.'i  jxnuids  ])er  inch.  If  the  vehx^ity  be  increased  to 
l,4')(i  feet  per  iiiinutf',  the  same  belt,  with  the.  same  tension,  will 
transmit  ten  )iorsi'-])ow('r.  So  that  a  (ive-inc.h  belt  apjjlied  to  a 
five-foot  jmlley,  making  120  revolutions  jier  minute,  would  tiaiis- 
luit  ten  liorse-power,  when  the  ellective  tension  is  225  poumls. 


BELTING.  43 

By  taking  the  actual  effective  tension  of  the  belt,  and 
mixltiijlying  it  by  the  actual  velocity,  we  get  what  may  be  called 
the  indicated  horse-power  of  the  belt,  which  corresponds  to  the 
indicated  horse-power  of  the  engine.  And,  finally,  by  measur- 
ing the  actual  power  transmitted,  which  may  be  done  by  means 
of  a  dynamometer,  we  can  get  the  actual  power  transmitted. 
Hules  based  upon  the  amount  of  belt  surface  in  contact  with  the 
pulley,  and  on  similar  data,  cannot  be  made  to  give  reliable 
results.  For  practical  purposes,  velocity  and  power  to  resist 
tension  are  the  only  available  elements  of  the  calculation.  Actual 
tension,  adhesion,  friction,  etc.,  can  all  be  varied  at  will,  and 
consequently  form  no  certain  dependence  for  the  calculations  of 
the  machinist  and  engineer. 

On  the  scientific  principle  that  the  adhesion,  and  conse- 
quently the  capability,  of  leather  belts  to  transmit  power  from 
motors  to  machines,  is  in  i^roportion  to  the  pressure  of  the  actual 
weight  of  the  leather  on  the  surface  of  the  pulley,  it  is  manifest 
that,  as  longer  belts  have  more  weight  than  shorter  ones,  and  that 
broader  belts  of  the  same  length  have  more  weight  than  narrower 
ones,  it  may  be  adopted  as  a  rule  that  the  adhesion  and  capabil- 
ty  of  belts  to  transmit  power  is  in  the  ratio  of  their  relative 
lengths  and  breadths.  A  belt  of  double  the  length  or  breadth  of 
another,  under  the  same  circumstances,  will  transmit  more  than 
double  the  power.  For  this  reason  it  is  desirable  to  use  long 
belts.  By  doubling  the  velocity  of  the  same  belt  its  effectual  ca- 
pability for  transmitting  power  is  also  doubled. 

Good  stock  is  the  first  requirement  of  a  belt,  which,  if  spongy, 
will  not  meet  that  demand.  It  must  be  firm,  but  pliable;  the 
grain  or  hair  side  should  be  free  from  wrinkles;  the  stock  should 
show  no  inequalities  in  dressing,  but  be  of  an  even  thickness 
throughout;  the  sialices  should  be  mathematically  true,  and  if 
rivets  are  employed  they  should  be  inserted  on  the  hair  side,  and 
the  burrs  sent  home  belore  riveting;  the  edges  should  be  parallel 
and  perfectly  straight.  In  handling  a  belt  examine  it  carefully, 
double  it  up  the  hair  side  out,  and  press  it  together.  If  it  crack 
under  this  treatment  it  should  be  rejected,  as  rational  use  of  a 
belt  consists  in  utilizing  the  whole  amount  of  power  it  will 
transmit. 

Belts  are  sometimes  used  having  a  transmitting  i:)ower  of 
double  the  cajjacity  necessary  where  they  are  employed,  while 
quite  as  often  they  are  much  too  narrow  for  tlie  work  required  of 
tliem  The  first  instance  shows  a  useless  waste  of  material,  the 
latter  poor  economy,  for,  in  order  that  it  may  i^erform  the  work 
required,  it  is  necessary  frequently  to  take  it  up,  as  a  result  of 
which  the  weak  points  succumb  to  the  strain  and  it  is  torn  asun- 
der, or,  if  not,  the  shaft  is  likel^^  to  be  drawn  out  of  line,  or  the 
bearing  overheated. 

Jit  asiiKj  a  new  Belt  a  few  days,  if  it  ijresent  a  mottled  ap- 
pearance on  the  side  next  to  the  pulleys,  it  may  be  set  down  that 
it  is  not  furnishing  the  full  capacity  of  its  power.  The  spots  re- 
ferred to  indicat.!  tlia*;  certain  portions  of  the  belt  do  not  touch 
the  pulley,  and  that  its  entire  transmitting  power  is  not  utilized. 


44 


BELTING. 


,  -  -  parts  of  tallow  to  one  of 
oil,  melted,  and  allowed  to  cool.  A  new  belt  should  be  used  a 
day  or  two  before  it  is  oiled,  and  frequent  applications  of  small 
quantities  are  better  than  too  liberal  oiliu!^  at  long  intervals. 

If  a  belt  of  the  proper  size  for  the  work  it  has  to  do,  slip  on 
the  pulley,  it  is  caused  by  the  centrifugal  force,  which  tends  to 
throw  it  outward;  a  corresponding  degree  of  tension  will  check 
the  defect. 

JBelts  sJioiild  he  jtnf  on  by  a  person  acquainted  with  their 
use,  as  the  wear  of  the  belt  depends  considerably  on  the  manner 
in  which  it  was  put  on.  Therefore  the  following  suggestions, 
if  practised,  will  be  of  much  service  to  persons  emidoyed  in  this 
capacity.  The  ends  to  be  joined  should  be  cut  jierfectly  S(iuare, 
in  order  that  one  side  may  not  be  drawn  tighter  than  the  other. 
Good  lace  leather,  if  properly  used,  will  give  b^'tter  satisfactioB 
than  any  patent  fastening. 

Wlteve  Belts  run  rertiedViij  they  should  always  be  drawn 
moderately  tight,  or  the  weight  of  "the  belt  will  not  allow  it  to  ad- 
here  closely  to  the  lower  pulley,  but  in  all  other  cases  they  should 
be  slack.  In  many  instances  the  tearing  out  of  the  lace  holes  is 
unjustly  attributed  to  jioor  belting,  when  in  railify  the  fault  lies 
in  having  a- belt  too  short,  and  trying  to  force  it  together  by  lacing; 
and  the  more  the  leather  is  stretelied  while  being  manufactured, 
the  more  liable  it  is  to  be  t-omplained  of. 

To  obtdin  the  (/rentest  antonnt  of  jtoirer  from  halts, 
the  pull'vs  shf>uld  be  covered  with  leather;  this  will  allow  tho 
belts  to  be  run  very  slack,  and  give  25  per  cent,  more  wear. 

More  power  can  b(!  obtained  from  using  the  grain  side  of  a  belt 
to  the  i)ulley  than  from  the  tiosh  side,  as  the  belt  adheres  more 
closely  to  tho  pulley;  but  it  should  be  remembered  that  the 
belts  will  not  last  quite  so  long,  for  when  the  grain,  which  is  very 
thin,  is  worn  off,  the  substance  of  the  belt  is  gone. 

Doable  LientUrr  Belts  are  frequently  used,  but  it  is  clearly 
a  mistake,  as  a  single  leather  one  will  transmit  more  of  the 
power  than  a  double  one.  DouM.'  leather  belts  run  straighter 
tiiaii  singl  ■  ones,  as  tli(!  Hank  side  <.f  diu;  part  can  be  jiut  against 
tht;  ba(;k  of  tlu;  ocher.  A  doul)!.;  leather  belt  will  stand  a  greater 
tension  than  a  single  one,  but  a  singl(>  belt  will  stand  all  that 
should  be  put  upon  any  belt. 

In  eases  where  a  belt  is  incapiibh-  of  transmitting  the  re(iuire(i 
niiioiint  of  jiower.  ainl  eireuiiistaiK^es  preelud(!  tlie  possil)ility  of 
Ku])stituting  a  wider  oni',  tiie  dilVKMilty  may  be  overcome  by  using 
two  belts  of  t'le  saiiK^  width,  one  oil  the  top  of  tlio  other.  Two 
belts  run  in  tliis  way  will  transmit  nearly  as  much  power  as  one 
belt  the  widtli  of  tli«-  two. 

Iloir  tit  test  the  iinafifff  of  Leather  for  Jteltintf.    Cut 

ft  small  strip  of  (lie  leatlier  about  olie-sixteelitil  of  all  inell  in 
lliii-luiess,  and  ])laee  it  in  strong  vinegar.  If  the  leatlier  has  been 
tliorouglily  taiiiied  an. I  is  of  good  (juality,  it  will  remain  for 
mouths  even,  immers(;d,  without  alteration,  simply  becoming  a 


BELTING.  45 

little  darker  in  color.     But,  on  the  contrary,  if  not  ttoroughly 
tanned,  the  fibres  -will  quickly  swell,  and  after  a  short  period  be- 
come transformed  into  a  gelatinovis  mass. 
How  to  make  Belts  run  on  the  centre  of  i)ulleys,—lt 

is  a  common  occurrence  for  belts  to  run  on  one  side  of  the  pul- 
leys. This  arises  from  one  or  two  causes.  1.  One  or  both  of  the 
pulleys  may  be  conical,  and  of  course  the  belt  will  run  on  the 
higher  side.  The  most  effectual  remedy  for  this  would  be  to 
straighten  the  face  of  the  pulleys.  2.  The  shafts  may  not  be 
parallel,  or  exactly  in  line.  In  this  case  the  belt  would  incline 
off  to  the  side  where  the  ends  of  the  shafts  come  the  nearest  to- 
gether. The  remedy  in  this  case  would  be  to  slacken  up  on  the 
Langer  bolts,  and  drive  the  hangers  out  or  in,  as  the  case  may 
be,  until  both  ends  of  the  shafts  become  parallel.  This  can  be 
determined  by  getting  the  centres  of  the  shafts  at  both  ends  by 
means  of  a  long  lath  or  a  light  strip  of  board. 

Tighteners. — The  tighteners  should  be  placed  as  close  to 
the  large  or  driving  pulley  as  circumstances  will  permit,  as  the 
loss  of  power  incurred  by  the  use  of  the  tightener  is  equal  to  that 
required  to  bend  the  belt  and  carry  the  tightening  prilley.  Con- 
sequently there  is  a  greater  loss  of  power  by  placing  it  near  the 
small  pulley,  as  the  belt  is  required  to  be  bent  more  than  when 
it  is  placed  near  the  large  one. 

The  reason  why  belts  run  to  the  highest  side  of  a  pulley  is  due 
in  part  to  a  centrifugal  force,  and  also  to  the  fact  that  the  part  of 
a  belt  nearest  to  the  highest  part  of  a  rounded  piilley  is  more 
rai^idly  drawn  because  the  circumference  of  the  pitlley  is  greater 
at  that  point. 

Rubber  and  Leather  Belts. — Rubber  belts  will  transmit 
nearly  as  much  power  as  leather  belts  with  the  same  tension;  and 
they  have  this  advantage,  that  they  may  be  made  of  any  length, 
width,  or  thickness,  and  yet  always  run  straight,  providing  the 
pulleys  are  in  line.  Besides,  their  first  cost  is  much  less  than 
those  of  leather,  but  they  will  not  last  over  half  as  long.  They 
cannot  be  run  in  situations  where  the  belt  rubs,  nor  as  cress- 
belts,  or  through  forks,  as  shifting  belts,  and  when  they  give  out 
it  is  almost  impossible  to  repair  them. 

If  a  Rubber  Belt  runs  off'  and  becomes  entangled  in  the 
machinery,  ten  chances  to  one  that  it  will  be  completelj-  ruined, 
whereas  a  leather  belt,  under  like  circumstances,  will  sustain 
very  little  injury.  When  saturated  with  oil  they  soon  rot,  and 
when  situated  in  cold  damp  places  they  are  liable  to  freeze, 
which  has  a  tendency  to  separate  the  different  thicknesses  and 
ruin  the  belt;  besides,  they  often  freeze  to  the  face  of  ptiUeys 
when  standing  still,  and  when  started  up  the  gum  facing  is  torn 
off,  which  ruins  the  belt. 

A  Leather  Belt,  if  made  of  good  stock,  not  overstrained 
and  properly  treated,  will  last  for  twenty  years.  When  partly 
worn  out  it  may  be  cut  and  used  over  again  for  a  narrower  or 
shorter  belt;  and  when  entirely  unfit  for  the  transmission  of 
power  it  may  be  tised  for  different  purposes  around  a  factory,  but 
wheu  rubber  belts  are  worn  out  they  are  of  no  value  whateTW 


46  BELTING. 

To  prevent  Accidents  by  shafts  revolving  M'itliin  reach  of 
operatives'  garments  in  mills  and  factories. — Cover  tliu  shaft  with 
a  loose  sleeve  of  sheet  tin  or  zinc,  and  insert  a  rim  of  thick  gnn 
or  leather  at  each  end  to  ^jrevcnt  rattling.  Should  it  become  en- 
tangled with  the  garments  of  any  of  the  operatives  the  resistance 
will  cause  the  sleeve  to  stand  still  while  the  shaft  is  rotating  within 
it,  by  which  means  the  person  may  be  extricated  and  accident 
averted. 

Itulef Of  finding  the  Lent/thof  Belt  wanted.— Add 
the  diameters  of  the  i)ulleys  together,  divide  the  sum  by  2,  and 
multiply  the  quotient  by  3|.  Add  the  product  to  twice'the  dis- 
tiince  between  the  centres  of  the  shafts,  and  the  sum  will  be  the 
length  required. 

jkufe  for  find  htf/  the  Width  of  Belt  to  transmit  a 
given  llorse- Poire r,—^l\\\ti\)\y  3G,OU0  by  tlie  number  of 
horse-power.  Multiply  the  speed  of  the  belt  in  feet  por  minute 
by  one-half  the  length  in  inches  of  belt  in  contact  with  smaller 
pulley.  Divide  the  first  product  by  the  second;  the  quotient 
will  be  the  r.'quircid  width  in  inches. 

Rule  for  calculaflng  the  Niiniher  of  Horse-Power 
a  Belt  ivill  transmit,  its  velocity,  and  the  number  of  s<|uare 
inches  in  contact  with  the  smaller  i)ulley  being  given. — Divide 
the  number  of  square  inches  in  contact  with  the  pulley  by  2; 
mu'tiply  this  (piotient  by  the  velocity  of  the  belt  in  feet  per  min- 
ute, and  divide  by  36,00).  The  quotient  is  the  number  of  horse- 
power the  belt  will  transmit. 

Another  Kille.—Dix'ule  the  number  of  s(juare  inches  of  belt 
in.  contact  with  the  pulley  by  2;  multiply  this  (pioticnt  by  the 
velocity  of  the  belt  in  feet  piT  minute;  dividi;  this  amount  by 
32,000,  and  the  (luotient  will  be  the  number  of  horse-power. 

Rule  for  tinding  the  change  re([uired  in  the  length  of  a 
belt  when  one  of  the  pulleys  on  which  it  runs  is  changed  for  one 
of  a  different  size. — Take  tliree  times  the  difference  between  the 
diameters  of  the  pulleys  and  divide  by  2.  The  result  will  be  the 
length  of  l)elt  to  cut  out  or  put  in. 

Htnv  to  midsnre  a  Coil  of  Belting.  XM  the  diameter 
of  the  hole  iu  inches  to  t!io  outside  diameter  of  the  roll-  mul- 
tiply Ijy  the  number  of  coils  iu  the  roll;  then  multiply  thi.s  by  the 
decimal  .1301),  and  the  product  will  be  the  number  of  feet  in  the 
roll.  To  hav(!  the  exawt  length,  the  average  diameter  must  b-i 
iisel,  if  the  roll  is  not  ])erfe.-tly  round,  and  fractional  parts  0.T 
an  inch  must  not  be  omilt",!  jn  the  calculation. 

Iloir  to  imt  (Hi  a  Brit.  -Never  place  a  belt  on  the  pullej 
in  motion;  always  place  it  liist  on  the  loo.se  pulley,  or  the  pnlle_^ 
at  rest;  then  run  it  on  the  pull(!y  in  motion.  If  the  belt  is  ver'v 
heavy,  and  the  pulleyH  run  at  a  very  high  speed,  it  is  advisable 
to  slack  on  the  sjieed  of  tli(!  engine;  but  when  this  is  imjiracrtica- 
ble  or  inconv(-nient,  care  must  Ix;  taken  to  mount  the  belt  on  the 
exact  face.  The  jierson  caigaged  in  so  doing  must  have  a  firm 
footing,  and  ])reveiit  his  clothes  from  getting  in  contact  either 
with  the  belt  or  pulley.  Where  the  belt  is  heavy,  and  the;  loca- 
tion such  that  it  is  impossible  to  got  a  Holid  footing  and  exert 


MOULDING  AND  FOUNDING.  47 

strengtli  in  running  on  tlio  b'lt,  it  is  best  to  stop  tlie  engine  and 
mount  the  belt  on  the  pulley  as  far  as  possible.  Then  take  a 
small  rope,  double  it,  slip  one  end  through  the  arms  and  around 
the  belt  and  rim  of  the  pulley,  and  the  other  end  throiigh  the 
loop  formed  by  the  double  of  the  rope;  then  stand  on  the  floor 
on  the  opposite  side  and  draw  on  the  rope,  when  the  belt  will  be 
hugged  to  the  periphery  of  the  iDullej'.  When  motion  is  com- 
municated it  may  be  slipped  on  without  any  trouble,  while,  by 
letting  go  the  end  of  the  rope  when  the  belt  is  on  the  pulley,  the 
noose  will  be  undone  and  the  rope  thrown  off.        — 


MOXTLDINa    AISTD    FOUNDING-. 


Tlie  crude  iron  of  the  blast-furnace  is  variously  disposed 
of  :  the  larger  portion  is  applied  to  the  manufacture  of  malleable 
iron,  while  the  remainder  is  converted  direct  into  innumerable 
articles  formed  of  cast  iron.  Occasionally,  the  smelter  carries  on 
the  founding  business  also  ;  in  which  case,  castings  are  frequent- 
ly made  by  running  the  molten  iron  direct  from  the  blast-furnace 
into  moulds.  At  other  times,  the  crude  iron  is  run  into  pigs  or 
bars  of  convenient  size,  allowed  to  cool,  and  then  charged  into 
other  furnaces  for  remelting.  This  plan  affords  facilities  for  ex- 
amining the  quality  of  each  piece  charged,  and  is  followed  when- 
ever great  soundness  is  required  in  the  castings, — as  in  the  case 
of  heavy  girders,  beams,  and  frame-work  of  engines ;  for  hydraulic 
rams,  and  similar  works  requiring  undoubted  strength. 

The  reiiieltilig  ftH'iUVCes  are  of  two  descriptions;  technical- 
ly, they  are  distinguished  as  "  air-furnaces  "  and  "cupolas."  The 
former  are  large  reverbatory  furnaces,  built  of  fire-brick,  having 
a  fire-grate  at  one  end,  from  whence  the  products  of  combustion 
pass  over  the  charge  on  to  the  flue.  The  floor  of  the  central  part 
is  made  sloping  to  the  divisional  bridge.  At  its  highest  part,  the 
charge  of  pigs  is  laid,  and  subjected  to  the  intense  heat  reflected 
from  the  fire-place  and  roof,  until  fused;  when  it  flows  over  the 
refractory  sand  bottom  to  the  hearth.  The  draught  is  maintained 
by  a  lofty  chimney,  bound  with  iron  hoops,  and  furnished  with 
a  regulating  damper  at  top. 

The  dhiiensioiis  of  f  lie  fit  maces  are  proportioned  to  the 
magnitude  of  the  work  genei"ally  pei'formed  in  them,  namely — 
from  3  to  10  tons  at  a  casting  ;  which  is  the  common  range  of 
their  capacity.  Doors  are  provided  on  one  side  for  charging  the 
pig-iron  and  supplying  the  fuel ;  and  on  the  opposite  side  is  a 
similar  opening  for  tapping  the  molten  iron  into  the  foundry. 
In  consequence  of  the  intense  heat  to  which  the  brick-work  of  the 
furnace  is  subjected,  a  systeoi  of  strong  plate  and  l)olt  binding  is 
adopted  to  retain  the  erection  in  position. 


48  MOULDIXa  AND   FOCNDING. 

TllC'  cupola  is  a  blast-furnaco  of  small  sizo,  in  wliicli  tlie  in- 
tonse  heat  necessary  for  fusion  is  maintained  by  a  fan  or  other 
blast.  The  interior  dimensions  measure  from  18  inches  to  3  or 
4  feet  in  diameter,  and  0  to  10  or  12  feet  in  height.  It  is  com- 
monly made  of  iron  plates,  bolted  together,  and  lined  inside 
with  the  best  fire-brick,  to  a  thickness  of  9  or  10  inches.  The 
blast  (cold)  is  supplied  through  one  or  two  tuyeres,  which,  for 
facility  of  operating  on  variable  quantities  of  iron,  are  so  made 
that  they  can  be  inserted  at  different  heights  of  the  furnace.  At 
the  bottom,  on  the  side  adjoining  the  foundry,  an  opening  is  left 
for  tapping  the  metal  and  removing  any  cinder  or  other  matter 
adliering  to  the  sides. 

Ettrh  of  fit-ese  renwUinf/  fuDUircs  possesses  certain  ad- 
vantages of  its  own.  The  air-furnace  is  prefi'rred  where  tough- 
ness and  a  homogeneous  structure  are  required  ;  the  slight  de- 
carbonating influence  of  the  reverberating  column  of  carbonic 
acid  and  other  products  of  combustion  from  the  fire-place,  ap- 
pears favorable  to  a  retention  of  strength.  The  iron  so  treated 
can  be  filed  and  chipped,  and  otherwise  cut  to  shape,  with  great 
facility.  It  contracts  less,  and  with  greater  regularity,  than  iron 
otherwise  treated. 

Cupolas  are  less  expensive  to  erect  where  a  supply  of  blat* 
can  bo  obtained  cheaply  ;  and  for  many  ojierations  are  ex- 
tremely useful.  Small  (quantities  of  iron  may  be  advantageously 
fused  and  by  means  of  ladles  conveyed  siuiuUnnt  ously  to  severel 
parts  of  the  foundry.  Castings  from  cupfdas,  however,  are 
weaker,  and  less  to  bo  depended  on,  than  those  from  air-furiiaces 
In  consefiuence,  also,  of  the  carbonizing  action  of  the  blast  on 
the  metal  in  the  furnace,  the  castings  prodiu'e<l  are  generally 
very  hard,  difficult  to  cut,  and  disposed  to  fly  (break  spon- 
taneously, through  unequal  contraction)  -whilst  cooling  ;  and 
even  afterward,  danger  is  to  be  apprehended  from  sudden 
changes  of  temperature.  The  tensile  strciigtli  is  inferif'r,  and 
prol)ably  arises  from  ))artial  disruption  of  the  cohesion,  through 
unequal  contraction  in  cooling. 

liji  the  foinnh'i't  iron  castings  are  distinguished  as  open 
sand',  green  saml,  dry  sand,  loam,  or  chillid  eastings,  according 
to  the  mode  of  moulding.  Occasionally  a  complex  i)iece  em- 
braces two,  or  even  all  tivo  methods.  Th(w;w-»  .wm/ method  is 
adapted  for  rough  articles,  such  as  flooriiig-idatcs,  and  other 
castings  inwhic^h  one  siile  is  permitted  to  be  uneven,  (ririii  sand 
numhluui  \h  largely  practised  in  tli<'  )>iodiiction  of  stove  fronts, 
pans,  small  jiipes,  and  the  innunnrable  small  articles  of  coin- 
merce.  phvin  and  ornamented,  of  cast-iron.  Ihij  sand  is  aiiplied 
to  largo  pipes,  engine  and  mill  work,  to  girders,  nnd  other  largo 
castings  ri'(Miiring  great  sireiiglh.  Tjoaia  is  a  mnditication  of  tho 
dry  sand  method,  and  is  priiii'ii)ally  apjdied  lo  large  circular 
castings,  sin^h  as  cylinders  and  wlieels.  C/iiUrd  cislimis  nro.  thoao 
cast  in  tliick  iron  inoulds  instead  of  sand  :  the  surface  of  the 
metal  in  contact  witli  the  cold  iron  is  ren.lereil  extremely  hard. 
in  consef|ur'nci'  of  the  sudden  manner  in  whi(di  it  is  coohid.  It 
ia  much  used  for  axle-boxes,  rollers  for  cofifco  and  sugar-mills, 


MOULDING  y  ND   FOUNDING.  49 

and  all  purposes  requiring  great  hardness,  and  capacitv  for  re- 
sisting abrasion. 

Open  sand  moulding.— MonhYmg  in  open  sand  is  the 
simplest  mode,  and  retiuires  comi)arativeIy  little  skill.  An  ex- 
act model  of  the  intended  casting  is  made  in  white  deal  wood, 
and  placed  in  an  excavation  in  the  danq)  sand  floor  of  the  mould- 
in"-bod,  the  top  level  with  the  floor  line.  Having  carefully 
levelled  the  model  with  a  T  level,  the  moulder  proceeds  to  ram 
the  sand  tightly  round  it  in  small  quantities  at  a  time,  with  the 
large  end  of  a  tamping-bar.  The  sand,  placed  in  contact  with 
the  model,  is  ^selected  with  care,  and  sifted  to  separate  any 
particles  of  iron.  On  attaining  the  level  of  the  model,  the 
tamping  is  discontinued,  and  the  sand  at  the  top  carefully 
smoothed  with  a  small  trowel ;  to  strengthen  the  edges  in  contact 
with  the  model,  a  few  drops  of  water  are  sprinkled  over  the  sand. 
With  a  large  iron  wire,  curved  so  as  to  pass  under  the  model 
without  touching  it,  the  moulder  jjiercis  the  sand  all  around 
several  times  ;  the  model  is  now  taken  out,  for  which  piirpose  an 
iron  spike  is  screwed  into  the  top,  and  repeatedly  struck  lightly, 
to  loosen  it  from  the  sand,  when  the  moulder  carefully  draws  it 
up.  To  facilitate  its  removal,  it  is  made  rather  larger  above 
than  beneath,  and  the  adhesion  of  sand  partially  prevented  by 
singeing  the  surface  of  the  wood.  In  the  event  of  any  i^orlion 
of  "the  "sand  having  been  detaclied  in  the  act  of  removing 
the  model,  the  damage  is  repaired  with  a  little  fine  sand, 
worked  with  the  trowel.  The  interior  is  then  dusted  over  with 
some  burnt  sand  from  previous  castings,  or  charcoal  dust  sifted 
thi-ough  a  horse-hair  sieve.  If  very  deep  for  an  open  sand  cast- 
ing, the  edges  of  the  mould  are  prevented  from  rising  by  a 
series  of  heavy  weights,  disposed  wherever  there  is  space. 
Shallow  castings  have  the  edg;s  of  the  mould  i^rotected  by  thin 
plates  :  in  all  cases  care  is  taken,  by  weights  or  sprigs,  that  the 
pressure  of  the  molten  metal  shall  not  lift  up  the  sand  wall. 
From  the  top  of  the  mould,  previous  to  withdrawing  the  mo  iel, 
a  small  canal  is  made  in  the  sand-bed  leading  to  the  smelting- 
furnace  or  to  a  small  pit,  into  which  the  inetal  is  poured  from  a 
Ix  lie.  The  communication  with  the  mould  is  closed  by  a  small 
iron  gate-plate,  loam-jl  over  to  prevent  the  adhesion  of  the  iron 
until  easting  time.  If  the  casting  be  deep,  the  canal  is  continued 
to  the  bottom  of  the  model  by  a  small  bore-hole,  at  a  few  inches 
dist.ince  from  the  body  of  the  intended  casting.  Large  castings 
require  two  or  more  branches  to  the  canal,  to  convey  the  iron  to 
different  parts  of  the  mould  simultaneously. 

T/ie  filliiif/  of  the  mould  demands  great  attention,  and 
requires  to  be  done  a-i  rapidly  as  may  be  practicable.  If  the 
metal  is  run  direct  from  a  furnace,  it  is  l)rought  simiiltaneously 
to  the  several  gates,  and  allowed  to  flow  into  the  diff'erent  parts 
of  the  mould  in  nearly  the  same  volume.  The  sprinkling  of  a 
few  drops  of  metal  around  the  air-holes  left  by  the  wire  produces 
a  slight  explosion,  throu'^h  ignition  of  the  inflammable  gases 
arising  from  them.  These  continue  to  burn  so  long  as  the  out- 
side of  the  metal  possesses  the  property  of  decomposing  water. 


50  JfOULDiyG   AND    FOUNDINa. 

The  molten  iron  is  carefully  skimmed  from  time  to  time,  and 
anj'  oxidized  matter  removed  from  the  surface.  If,  at  the  termi- 
nation of  the  running,  themoull  appears  to  be  filling  unequally- 
the  defect  is  remedied  by  the  adjacent  stop-gates  being  opened 
or  shut,  as  the  circumstances  may  rcqiiire.  The  molten  iron  is 
never  poured  direct  from  a  vessel  into  the  mould;  but  in  a  mould 
partly  filled,  it  is  somethues  allowed  to  flow  direct  from  the  ladle. 
The  running  finished,  the  surface  of  the  metal  is  usually  sprin- 
kled with  a  little  dry  san  1,  and  the  casting  left  in  its  bed  until 
sufficiently  cold  for  removal. 

Jf  sotiudiiess  is  rcqtih'ed,  no  casting  of  any  kind  should 
be  removed  until  cooled  down  throughout  to  witliiu  a  few  de- 
grees of  the  atmosphere;  and  in  the  case  of  open-run  castings,  a 
thick  covering  of  sand  should  be  applied  to  retain  the  heat.  If 
removed  too  soon  after  casting,  the  piece  is  irreparably  weak- 
ened, if  not  fractured  and  lost.  Want  of  room  in  a  confined 
foundry  is  commonly  adduced  as  a  reason  for  turning  out  the 
work  as  soon  as  it  has  solidified  ;  but  a  desire  to  turn  out  more 
■work  than  the  foundry  is  capabh^  of  producing,  is  perhaps  nearer 
the  mark.  Fivnn  whatever  cause  it  may  arise,  it  is  too  evident 
that  many  disastrous  accidents  have  arisen  from  the  breakage  of 
girders  and  mill  machinerj',  resulting  solely  from  inattention  to 
this  point,  thus  occasioning  great  mistrust  in  cast  iron  as  a  ma- 
terial of  construction,  and  lowering  its  commercial  value. 

Gl'Cf'H  sditd  c<fstin(/s  differ  iVom  open  SiUid,  in  being  cov- 
ered with  th(!  half  of  a  box  during  the  process  of  easting. 

The  green  sand  of  the  founder  is  an  argillaceous  sand,  in  the 
state  in  which  it  is  raised  from  the  gravel-pit,  having  been  first 
sifted  through  a  fine  with  sieve,  carefully  mixed  witli  about  one- 
twelftli  of  its  volume  of  finely  powdi'red  coal,  and  slightly  moist- 
ened with  water;  in  this  state  it  retains  tlm  exact  form  of  any 
object  impressed  on  it.  This  mixture  can  only  be  used  once  for 
the  formation  of  moulds,  being  afterward  employed  for  filling 
up.  In  order  to  obtain  tlie  form  of  the  })attc;rn,  tlie  moulder 
takes  a  cast-iron  frame,  which  is  filled  with  sand  and  closely 
rammed.  Taking  the  pattern  from  which  the  casting  is  to  bo 
made,  the  workman  scratches  on  the  smootli  surface  of  the  sand, 
and  in  the  centre  of  tlie  iron  frame,  a  rougli  resemblance  of  the 
moihtl,  wliicli  is  iudjcdded  into  tli(!  sand  to  one-half  of  its  thick- 
ness; it  is  then  si)iinkle(l  ov('r  with  charcoal  dust. 

A  counterjjart  of  the  cast-iron  frame  is  now  filled  in  a  similar 
maniKT  with  sand  closely  jmcked,  dusted  over,  also  with  char- 
coal dust,  and  ]>laced  ui)on  tlie  model  ;  by  this  process  a  mould 
of  t!i(!  other  half  is  impressed  upon  it,  the  cliareoal  dust  i)revent- 
ing  any  adhesion  betwpfai  the  two  parts  of  the  frame.  Tin'  upper 
fraiiu!  is  now  carefully  raised,  aiul  the  model  removed  from  tlio 
lower  frame,  any  slight  iinperfeetiou  in  the  mould  being  r(>])aired 
by  till!  use  of  a  little  moistened  sand  and  a  small  trowel  shaped 
for  tlu!  purpose.  The  two  j)arts  of  tlio  frame  arc;  now  joined  to- 
gether by  means  of  eornsjionding  jjins  and  holes,  and  a  cavity 
remains  of  the  form  of  the  requircMl  easting. 

SitKill  (li'ticlcH  uluo  liavo  a  bottom  box,  and,  if  of  a  complex 


MOULDIIvG  AND  FOUNDING,  51 

form,  may  require  several  boxes  for  their  complete  formation. 
Pulleys,  for  instance,  require  a  three-part  box — a  top,  middle, 
and  bottom.  The  moulding  boxes,  whether  for  green  or  dry 
sand,  are  made  of  cast  iron,  with  cross  ribs,  wherever  the  nature 
of  the  model  permits,  for  holding  the  damped  sand.  The  sepa- 
rate parts  are  made  to  iit  each  other  accurately  by  taper  pins, 
through  which  keys  are  driven  to  bind  the  several  parts  lirmly 
together  during  the  operations  of  moulding  and  casting.  If  the 
several  parts  of  the  box  are  large,  requiring  the  assistance  of  a 
crane  for  handling,  each  part  -is  furnished  with  trunnions,  on 
which  it  is  turned  over,  and  its  under  side  dressed  up  by  the 
moulder.  The  filling  of  the  mould  is  conducted  in  much  the 
same  manner  as  with  o^Den  castings,  a  suitable  jet  being  left  for 
the  escape  of  confined  air. 

The  tnoiildhiff  of  imUens,  as  requiring  a  three-part  box, 
very  well  exemplifies  the  principles  of  the  art.  The  model  of  the 
pulley  is  made  in  two  halves,  fitting  each  other  with  suitable 
drilling  pins.  If  several  are  to  be  cast  from  the  same  model,  a 
cast-iron  one  is  commonly  made  from  a  wood  pattern,  and  sub- 
sequently fitted  to  remove  any  asperities  on  the  siirface.  In  the 
bottom  part  of  the  box  the  lower  side  of  one-half  of  the  model  is 
moulded,  all  superfluous  sand  removed,  the  exposed  portions 
carefully  smoothed  over,  and  fine  charcoal  dusted  over  it.  The 
upper  half  of  the  model  is  fitted  on,  and  the  middle  part  of  the 
box  clamped  down.  In  this  portion  of  the  box  the  hollow  edge 
of  the  pulley  is  moulded.  The  sand  is  again  smoothed  down, 
and  the  surface  dusted  preparatory  to  re-covering  the  top  part  of 
the  box.  This  is  placed  on  the  middle  part,  and  the  upper  side 
of  the  pulley  moulded  in  it.  Having  left  an  orifice  for  the  en- 
trance of  the  metal,  and  another  for  the  escajje  of  the  air,  the  top 
part  is  lifted  ofi",  with  the  upper  half  of  the  model  adhering  to  it. 
The  middle  part  is  next  lifted  off;  this  is  a  mere  ring  of  sand, 
filling  up  the  hollow  j^eriphery  of  the  pulley.  After  removing 
the  halves  of  the  model,  the  parts  of  the  box  are  replaced,  pre- 
paratory to  casting.  The  charcoal  dust  prevents  the  sand  in  one 
part  from  adhering  to  that  in  the  others. 

DriJ  sand  Cftufinffs  are  usually  prepared  in  boxes  similar 
to  those  used  by  green  sand  moulders.  'J  his  is  more  especially 
needful  where  a  great  weight  of  metal  is  to  be  cast  in  moulds 
made  of  this  material  Dry  sand  is  generally  used  without  any 
admixture  of  coal  dust.  Castings  made  in  this  material  are  less 
liable  to  imperfections  and  air-holes  than  those  prepared  in  ordi- 
nary green  sand  moulds,  its  porous  nature  permitting  of  a  freer 
escape  of  the  gases,  while  there  is  less  chance  of  its  chilling  in 
the  mould  from  the  baking  process  which  it  undergoes  before 
introducing  the  metal. 

Ill  (ill  cdsthnj  pt'occKscs,  much  of  the  success  of  the  oper- 
ation depends  on  the  skilful  manipulation  of  the  moulder;  on  him 
must  depend  the  adjustment  of  the  mould,  and  the  weight  of  the 
metal  with  which  it  is  charged,  the  due  admixture  of  the  ma- 
terials, with  that  degree  of  porousness  necessary  for  the  escape 
of  the  gases  as  they  are  genei-ated  by  the  fluid  metal. 


52  MOULDING  AND  FOUNDING. 

When  complete,  the  several  parts  of  the  box  are  taken  sepa- 
rately to  a  large  oven,  or  drying-stove,  and  tlioronglily  dried,  to 
expel  all  moisture  from  the  sand.  Afterward  the  interior  of  the 
mould  is  blackened  with  thick  washes  of  ground  charcoal  or 
coke,  worked  up  with  water  to  a  2iroi)er  consistence.  It  is  again 
dried,  and  the  several  parts  adjusted  to  each  other.  If  the  box 
seems  to  require  strengthening  before  the  performance  of  casting, 
it  is  sunk  in  the  sand,  level  with  the  floor  of  the  foundry,  and  on 
the  upper  jjart  are  laid  several  heavy  weights,  siipplemental  to  the 
side  keys,  in  keeping  the  structure  rigidly  together  under  the 
pressure  of  the  li(juid  iron. 

Several  peculiar  configurations  of  cast  iron,  also  such  holes  aa 
as  may  be  required  in  tlie  castings,  whether  large  or  small,  are 
formed  with  cores,  or  loose  pieces  of  sand,  strengthened  wherever 
necessary  by  internal  iron  bars  and  frames.  These  cores  are 
made  by  tightly  ramming  the  best  sand  in  iron  or  wooden  boxes 
of  the  required  shape,  and  then  placing  them  in  the  stove  to  dry; 
subsequently  they  are  blackened,  and  treated  as  the  other  parts 
of  the  mould.  By  means  of  a  system  of  hollow  and  solid  cores, 
all  castings,  whatciver  be  their  configuration,  may  be  made  with 
comparative  facility;  and  not  unfrequently  pieces,  the  construc- 
tion of  which  would  se(>m  to  involve  difficulties,  are  made  with 
only  a  few  core-box(^s  and  a  plain  model. 

Lo(nn  itionUlimj  differs  from  the  other  methods,  inasmuch 
as  no  models,  or  core-boxes,  are  used;  but  the  moulds  are  made 
directly  from  drawings  of  the  objects  to  be  i^roduced.  The 
mould  is  made  of  a  mixture  of  clay,  water,  sand,  and  cow-liair, 
which  is  first  reduced  to  a  paste,  and  thorougldy  kneaded  in  a 
pug-mill.  This  mass  is  made  to  assume  the  re<£uired  form  by 
the  use  of  various  instruments;  the  proportions  of  the  various 
ingredients  being  changed  to  suit  difler<nt  purposes.  The  prep- 
aration of  the  loam  mould  is  frei^nently  a  dillicult  jjrocess,  re- 
quiring a  skilful  moulder,  as  he  is  sometimes  reciuircd  to  shape 
and  mould  very  comi)licatcd  forms  with  only  his  eye  to  regulate 
his  tools.  The  i)rofilo  of  the  circumference  of  the  required  cast- 
ing is  cut  on  a  stout  board,  and  attached  at  tliore([uiKite  radius  to 
a  rigid  iron  spindle,  which  freely  turns,  vertieally,  on  suitable 
bearings.  The  mould  for  a  large  cylinder,  for  instance,  is  com- 
menced at  tlie  bottom  ofadryi)it  in  the  foundry,  l)y  laying  ft 
course  of  brick-ends  on  the  loami^d  l)ottom  to  the  reach  of  the 
sweep-board,  and  covering  their  upi)er  surface  and  face  witli  a 
layer  of  loam  (sand  workecl  U])  to  the  consistence  of  thin  mortar, 
Ktrengtliened  by  some  weak  fibrous  subslantu^).  The  board  is 
now  swept  around,  remnviiig  any  superlluiMis  loam,  and  a  second 
course  of  bricks  laid  on  tlie  first;  luam  is  added;  an<l  in  this 
manner  a  rough  wal  of  th<^  recpiired  height  is  l»uilt.  'i'luMnsido 
is  \v(.'ll  ])lasterod  wiih  loam,  wiiich  is  wrought^  to  the  ))re(use  form 
liy  sweeping  around  the  board,  and  finished  with  a  coat  of  tine 
material.  W'Ik  n  the  outsule  of  tlu^  mould  is  eoinph'te,  the  hoard 
is  taki  11  out,  and  a  grate  with  lighted  lire  suspended  in  it,  (o 
(fleet  a  t'lorough  drying;  subse({uently  it  is  blaekeneil  luul  a;'ain 
dried.     The  core  is  built  in  a  similar  maini' r,  on  a  (•ireulai-  plid- 


MOULDING  AND  FOUNDING.  53 

form  of  the  required  size,  which  revolves  while    being  built 
against  a  fixed  loam-board. 

Cores  for  pipes  and  smaller  cylinders  are  built  aroiind  a 
hollow  cylindrical  core-bar,  pierced  with  numerous  holes  and 
open  at  the  ends,  with  the  exception  of  the  space  occupied  by  the 
trunnions.  Around  this  cylindrical  bar  is  laid  a  covering  of  hay 
or  straw  rope,  and  then  the  usual  coating  of  loam,  drying,  and 
blackening.  The  gases  generated  in  the  casing  of  the  core-bar 
escape  through  the  small  holes  into  the  hollow  cavity  of  the  core- 
bar,  and  out  at  the  ends,  where  they  are  ignited.  The  hay-bands 
freely  allow  of  the  pipe  contracting  in  cooling,  which  it  could 
not  do  around  a  solid  substance,  and  permit  of  the  ready  with- 
drawal of  the  bar. 

The  )nouldhig  of  a  large  gear-wheel  may  be  taken  as 
an  ilhistration  of  the  manner  in  which  castings,  partly  in  loam 
and  partly  in  dry  sand,  are  worked  up.  The  moulding  of  a 
wheel  with  four  arms  is  accomplished  bj^  loaming  a  level  surface 
in  the  wheel-pit,  and  arranging,  by  means  of  a  trammel  working 
from  the  centre,  a  number  of  tooth-cores  made  in  the  core-box. 
The  model  teeth  in  this  box  are  iisually  loose,  and  kept  in  their 
jDlace  by  passing  through  mortises  in  each  side;  the  two  sides  are 
kept  together  while  tamping  by  clamps.  Four  arms  are  formed 
by  the  same  number  of  moulds,  whi'e  a  third  box  forms  the  cen- 
tre core.  Great  accuracy  is  required  in  the  setting  of  the  cores; 
and  allowance  has  to  be  made  for  contraction  of  metal  in  cooling. 

A-il  i iispecfion  of  the  process  will  convey  a  correct  ideaof  the 
way  in  which  many  moulds  are  built  up  at  comparatively  trifling 
expense;  and  it  is  to  be  borne  in  mind  that  the  binding  together 
of  the  several  jDarts  of  the  boxes  and  frames,  by  means  of  the 
taper-pins  and  cross-keys,  previous  to  pouring  in  the  molten 
metal,  is  an  operation  requiring  great  care  on  the  part  of  the 
operator. 

Liquid  cast  trow- presses  with  a  force  exceeding  one  pound 
the  square  inch  when  the  column  is  four  inches  high.  Castings 
are  frequently  made  and  cast,  with  a  column  of  liquid  iron  ten 
feet  high  ;  in  which  case,  every  inch  of  the  mould  exposed  to 
this  column  has  to  resist  a  bursting  pressure  of  more  than  thirty 
pounds,  or  about  one-half  the  pressure  to  which  high-pressure 
steam-boilers  are  subjected.  Under  such  circumstances  the 
boxes  require  to  be  of  great  strength,  perfectly  rigid,  and  bound 
together  at  short  intervals  with  heavy  iron  bands,  in  addition  to 
the  pins  and  keys.  In  green-sand  moulding,  the  column  of 
metal  is  \isually'much  less  ;  but  the  surface  extended  horizon- 
tally demands  nearly  the  same  x^recautionary  measures. 


54  PROPERTIES    OF    CAST   IRON. 

THE     STRENG-TH     AND      OTHER 
PROPERTIES  OF  CAST  IRON. 


The  properties  of  iron  of  greatest  importance  in  construction 
and  mechanical  engineering  are— 1,  tenacity  ;  2,  transverse 
strength  ;  3,  power  to  resist  impact ;  4,  power  to  resist  fatigue  ; 
and  5,  power  to  resist  compressing  or  crushing  forces  :  to  these 
must  be  added,  in  the  case  of  the  founder  and  turner— 5,  fluiditj^; 
6,  hardness  ;  and  7,  texture.  For  special  purposes,  other  quali- 
ties are  sometimes  sought  after,  but  the  foregoing  comprise  the 
essentials  required  in  a  good  cast  iron. 

It  is  well  known  to  founders  and  mechanical  engineers,  that 
the  several  qualities  for  which  a  given  cast  iron  may  bo  dis- 
tinguished, are  susceptible  of  considerable  modification,  improve- 
ment, and  more  marked  development,  by  special  treatment  in 
the  hands  of  the  founder  ;  and  to  smelters,  that  the  general 
qualities  of  the  original  crude  pig-iron  are  dei^endent,  in  great 
measure,  on  the  chemical  composition  of  tiie  ores,  fuels,  and 
fluxes,  and  in  the  smclting-furnace  :  but  with  similar  materials, 
the  method  of  working  the  furnace,  the  temperature  of  the  blast, 
the  construction  of  the  furnace  itself,  and  various  other  causes, 
are  found  to  exercise  important  influences.  The  crude  iron  of 
the  blast-furnace,  however,  is  rarely  used  for  the  formation  of 
valuable  castings,  until  it  has  iindergoue  one  or  more  remeltings; 
and  the  following  remarks  will  a2)ply  only  to  iron  which  has 
been  reworked  in  this  manner. 

The  importance  to  the  engineering  profession,  and  to  science 
generally,  of  an  elaborate  series  of  experiments  on  the  qualities 
of  cast  iron,  has  been  very  generally  felt  for  the  last  (quarter  of 
a  century  ;  but  the  time  required  for  their  prosecution,  and  the 
expense  necessarily  involved,  have  been  too  great  for  any  ])rivato 
individual.  Several  engineering  firms  have  made  a  few  experi- 
ments on  the  metal  as  j)reliminary  trials,  ])revious  to  the  execu- 
tion of  particular  works  ;  and  the  ]>ritish  Association  for  tho 
Advancement  of  Science  allotted  a  small  sum  of  money  for  somo 
limited  experiments  on  form  and  a])plication.  More  recently  a 
commission  was  issued  by  Government  to  inquire  into  the  'n\i- 
j)li(ration  of  iron  to  railway  structures  ;  but  its  labors  were  con- 
fined to  t<5sting  the  stability  of  a  few  railway  bridges,  and  col- 
I(!cting  the  verl)al  opinions  of  engineers  as  to  the  merits  of  j)jir- 
ti(!ular  brands  of  jjig-iron  :  the  results  of  the  inquiry  were  of 
little  or  no  valu(!  to  practical  workers  in  tho  metal. 

In  the  United  Staten,  the  great  difl'erenco  observed  in 
the  strength  and  durability  of  cast-ironordnance,  ajiparentlycom- 
ixiseflof  equally  gf)od  metal,  le(l  fn  I  lie  u<lo])t  ion  of  ineasuri's'f'or  as- 
certaining tlie  cause  of  siieh  ditleniiiie.  'I'hese  measures  weri!  first 
iijjplied  about  fliirtcen  years  siin-e,  and  coinlucfed  out  of  tho 
public  revenue  of  tlio  States  by  coni])etent  and  highly  jiains- 
taking  ollicora  of  engineers  :   tho  results  as  published  form  tho 


PROPERTIES    OF    CAST   I?.ON.  55 

most  complete  and  reliable  record  of  experimental  researches  on 
the  metal  yet  issued  in  any  country  ;  and  contrasts  most  favor- 
ably with  the  manner  in  whicli  similar  researches  are  under- 
taken and  conducted  in  England.  From  this  work,  and  from 
private  researches,  will  be  collected,  in  a  condensed  form,  a  few 
of  the  principal  known  focts  relating  to  the  qualities  of  cast  iron. 


Tensile  Strengtli  of  Cast  Iron. 

In  all  purposes  to  which  cast  iron  is  applied,  tenacity  is  a 
quality  of  the  iirst,  if  not  of  paramount,  importance.  Transverse 
strength,  the  next  in  the  order  of  importance,  is  directly  depend- 
ent on  the  tenacity  of  the  metal.  Hence,  in  all  well-conducted 
researches  into  the  qualities  of  pig-iron,  tenacity  takes  prece- 
dence of  the  others.  It  is  influenced  by  several  causes,  sepa- 
rately and  combined;  the  chief  of  these,  so  far  as  yet  ascertained, 
is  — 
Temperature  of  the  Blast  used,  in  the  Reduction 

of  Cast  Iron. 

With  the  invention  and  application  of  the  hot-blast, 
there  arose  a  very  general  belief  f'uat  tlie  new  jirocess  tended  to 
largely  deteriorate  the  tensile  strength  of  the  pig-iron  produced. 
With  the  existing  furnaces,  however,  the  invention  in  one  dis- 
trict eifected  such  a  considerable  saving  of  coal  in  the  furnace, 
that  the  generally  inferior  character  of  the  iron  i>repared  with  it 
■was  controverted  by  the  manufacturers.  And  at  the  present  day 
the  inferiority  is  very  frequently  ascribed  by  writers  to  the  facili- 
ties which  this  invention  affords  of  working  up  materials  of  a 
quality  inferior  to  those  capable  of  being  reduced  by  a  cold 
blast.  Recent  reseai'ches,  however,  have  demonstrated  that,  with 
similar  ores,  fuel,  and  flux,  the  quality  of  hot-blast  iron  is  greatly 
inferior  to  that  of  iron  smelted  with  a  cold-blast. 

The  experiments  made  for  the  British  Association,  with  a 
view  of  settling  this  point,  were  the  Iirst  of  their  kind  jniblicly 
undertaken;  and  the  results  are  subjoined  : 

Tenacity  iu  lbs. 
per  sq.  in. 

Carron  No.  2  quality  pig-iron hot-blast,  13,505 

cold  "  16,683 

"       No.  3  quality  pig-iron hot  "  17,755 

"  "  "  cold  "  14,200 

Coed  Talon  No.  2  quality  pig-iron hot  "  16,676 

"  "  cold  "  18,855 

Bufferey  No.  1  quality  jiig-iron   hot  "  13,434 

cold  "  17,4iJ6 

The  number  of  pig-irons  tested  was  sixteen ;  and  it  will  be  ob- 
served that,  with  one  exception,  the  cold-blast  irons  are  greatly 
superior  to  the  hot.  The  single  exceptional  case  led  the  experi- 
menters to  the  conclusion  that  the  lower  qualities  of  iron  were 
improved  by  the  use  of  hot  air  to  nearly  the  same  extent  as  the 


56  PROPERTIES    OF    CAST    IRON. 

higher  qualities  were  deteriorated.  This  conclusion,  however, 
was  founded  on  a  single  exijeriment;  and  to  have  been  of  any 
value,  a  fresh  portion  of  iron  should  have  been  taken  and  exper- 
imented on  for  corroboration  of  such  a  striking  anomaly. 

l*revioiis  to  tJiese  experhnents,  the  Low  Moor  Company 
— whose  works  in  the  Bradford  district,  ^yell  known  for  the 
superior  quality  of  the  iron  i^rodviced  in  it,  had  been  wrought 
entirely  with  cold-blast— adoj^ted  the  new  mode  of  smelting;  but 
the  reduction  in  quality  was  such  that  the  cold-blast  was  re- 
sumed after  a  very  brief  trial.  These  and  the  other  works  in 
this  district  have  since  continued  to  use  a  cold-blast  only.  Ex- 
periments were  made  on  the  Low  Moor  irons  as  prepared  by  the 
two  processes,  and  the  lollowing  results  obtained,  the  strength 
of  cold-blast  iron  being  taken  as  unity: 

Mean  breaking  weight  of  cold-blast  pig-iron    1.000 

hot     "  "         831 

Snhseqjientlij  experiments  were  made  at  the  Dowlais 
Works  on  irons  renielted  in  an  air-furnace,  also  on  others  re- 
melted  in  the  cupola,  with  results  nearly  the  same  as  those  oc- 
curring at  Low  Moor,  the  relative  strengths  being: 

Mean  breaking  weight  of  five  bars  of  cold-blast  iron,  1.000 
"  "  "  six  bars  of  hot-blast  iron,       .835 

The  (liscoverij  that  a  cold-blast  of  sufficient  density  could 
be  successfully  used  in  fonang  furnaces  using  anthracite  fuel, 
resulted  in  some  comparative  trials  being  made  at  the  Ystalyfera 
works  on  irons  prepared  by  the  two  processes.  The  result  of  a 
large  number  of  experiments  tended  to  establish  the  fact  of  a 
large  deterioration  occurring  with  the  hot-blast  irons,  the  rela- 
tive strengths  of  the  two  irons  being: 

Anthracite  iron,  cold-blast  1.000 

"     hot-blast 802 

TJiese  e,rpei'hnents,  miulo  on  irons  reduced  from  similar 
ores  and  under  circumstances  precisely  etjual,  temi)eraturc  of 
of  blast  excepted,  must  be  luild  ci  inclusive  as  far  as  regards  the 
irons  of  that  country.  The  experiments  in  the  United  States 
were  made  principally  on  charcoal  irons;  nevertheless,  the  re- 
B)ilts  are  even  more  unfavorabh;  to  the  h<)t-blast  irons.  The  di- 
minntif)n  of  tenacity  which  fillows  on  the  heating  of  the  blast,  is 
shown  in  the  following  statement  of  the  effects  produced  on  the 
American  furnace  iron; 

TenBilc  BtrciiKth  iu 
lbs.  por  Bq.  iu. 
IJlilHtCold     11,110 

'•     heated  to  150'-" r2,'2i;i 

'MP 1'2,!)70 

250' 11,420 

This  pi^f-iron  was  <if  No.  1  (piality,  and  oast,  for  the  pur- 
pose of  experiment,  into  liars  in  the  ojjcn-sand  furnace-bed. 
The  difference  in  the  tensile  strength  of  hot  and  cold  blast  iron 


PROPERTIES   OF    CAST   IRON.  57 

from  the  same  farnace  was  so  great  in  several  instances,  that  the 
officers  engaged  in  the  inquiry  sought  and  obtained  the  moht 
ample  proof,  that  in  every  case  the  inferior  metal  had  been  pro- 
duced from  hot-blast  iron.  In  the  case  of  seventeen  guns  cast 
from  hot-blast,  eight  failed  to  stand  the  proof.  Experiments  on 
the  metal  in  three  guns  gave  a  density  of  7.ii9  and  a  tenacitv  of 
2U,732  lbs.  to  the  square  inch.  Similar  experiments  on  guns  east 
at  the  same  works  several  years  previously,  but  from  cold-blast 
iron  gave  a  density  of  7.185  and  a  tenacity  of  25,24(3  lbs.  to  the 
square  inch. 

It  is  worth  II  ofremarJx,  also,  as  bearing  out  the  opinion 
that  the  quality  of  English  pig-iron  has  deteriorated  within  the  last 
half  century,  that  in  an  English  gun  imported  into  America  in 
1845  the  cast  iron  was  of  a  density  of  7.0i,  and  tensile  strength 
of  18,145  lbs.  to  the  square  inch  ;  while  other  English  guns  im- 
ported about  thirty  years  previously  contained  metal  of  a  density 
of  7.202,  and  tensile  strength  corresponding  to  28,Oo7  lbs.  to  the 
square  inch. 

The  analj/ses  made  in  the  laboratory  attached  to  the  Pikes- 
ville  Arsenal  are  singularly  confirmatory  of  the  unfavorable  opin- 
ion respecting  the  hot-blast  current,  soon  after  its  introduction. 
The  results  of  numerous  analyses,  on  irons  prepared  by  the  two 
processes,  gave — 

Cold-blast.     Hot-blast. 

Specific  gravity 7  194         7.074 

Tensile  strength 26,859       18,993 

Combined  carbon 0836  .0687 

Graphite 0476  .0600 

Silicium 0386  .0593 

Slag 0189  .0375 

Phosphorus .0228  .0185 

Sulphur 0(114  .0010 

Manganese 1141  .0900 

Earths   0117  .0146 

Silicium  and  carbon 1219  .1281 

Silicium  and  slag 0575  .(938 

Graphite  and  slag 0065  .0975 

Graphite,  slag,  and  silicium. 1051  .151  8 

Graphite,  slag,  silicium,  and  phosphorus  ..     .1280  .1753 

Total  carbon 1312  .1287 

Graphite,  slag,   silicium,   phosphorus,  sul- |     -.,^.  lono 

phur,  and  earths )    '^^^^  '^^^^ 

Hie  result  of  the  numerous  experiments  made  in  the  United 
States  on  cast  irons  has  been  the  entire  rejection  of  hot-blast 
smelted  iron  as  a  material  for  constructing  ordnance.  It  must 
not,  however,  be  supposed  that  hot-blast  iron  is  inapplicable,  or 
inferior  to  cold-blast  irons,  for  all  purposes.  "Where  great  ten- 
sile strength  is  desired  it  should  be  carefully  avoided;  butimder 
other  circumstances,  it  may  frequently  be  substituted  for  cold- 
blast  iron  with  considerable  advantage. 
3* 


58  PROPERTIES    OF    CAST   IRON, 

Jtemelthig  the  crude  iron  lias  an  important  influence  on 
its  tensile  properties.  An  improvement  in  quality  is  very  gen- 
erally observed  on  reaielting  the  crude  pig-iron  of  the  blast- 
furnace in  reverberatory  furnaces.  "With  founders  this  improve- 
ment is  ascribed  to  the  more  homogeneous  character  of  the  iron 
so  treated,  over  that  of  the  original  pig;  but  the  author,  in  his 
large  work,  combated  this  opinion,  and  placed  it  to  the  credit  of 
the  refining  of  the  iron  which  necessarily  takes  place  at  each  re- 
melting.  The  publication  of  the  American  experiments  confirms 
this  view  of  a  mere  remelting  resulting  in  the  production  of  a 
jjurer  metal. 

Crude  piif-iroil  of  the  blast-furnace  was  taken  and  thrice 
remelted  to  observe  the  change  of  quality  and  increase  of  density 
produced;  the  results  were  : 

Tensile  Btrength 
Density,     iu  lbs.  per  sij.  iu. 

Crude  pig  iron  0,974 14,000 

remelted  once 7.000 20,900 

twice 7.229 30,229 

"  "  "         three  times.    7.301   35,786 

In  a  second  scries  of  experiments  the  improvement  in  quality, 
by  remelting,  was  eipially  marked.  The  metal  operated  on  was 
coUl-blast  charcoal  pig-iron,  cast  in  similar  moulds  and  under 
similar  conditions,  the  number  of  fusions  alone  excei)ted  : 

Tfusile  Btrength  iu 

lbs.  per  sq.  iu.      Density. 

Crude  pig-iron   11,020 6.949 

remelted   15,942 7.009 

•«  "  "        twice. 35,840 7  327 

In  another  case,  the  iron  of  third  fusion  attained  a  density  of 
7.304,  and  tensile  strength  of  4), 970  poumls  per  square  inch— 
the  highest  ever  sustained  by  cast  inm. 

Experiments  on  a  limited  scale  were  made  for  the  15ritish  A.s- 
Bociation  by  Mr.  Fairbairn  ;  and  the  results,  though  less  marked 
tlian  the  American  experiments,  demonstrate  tlic  great  ad  vantages 
which  may,  in  many  instances,  be  derived  from  a  mere  remelting 
of  the  cast  iron. 

One  ton  of  I'glinton  hot-blast  iron  was  operated  on,  and  the 
pr  ,)i)ortii)ii  of  flux  an  I  coke  at  each  fusion  accurately  measured, 
HO  iis  to  bo  alike  at  each.  The  iron  was  run  into  bars  one  inch 
sipiare,  and  the  trials  were  made  on  lengths  of  about  four  feet, 
KUpport<:d  at  each  end,  and  the  weiglit  applied  in  the  centre 
gralu;illy,  until  tlie  bur  broke:  one  bar  was  reserved  at  each 
trial,  and  the  rest  of  the  iron  again  remelted.  This  succession 
of  roMK^llings  and  trials  was  repeated  seventeen  times,  when  the 
quantity  of  iron  wits  too  mueli  nuluced  for  a  continiianee  of  the 
(experiments.  The  results  obtaincMl  prove  that  cast  iron  ini^reassos 
in  slnsngth  up  to  the  twelfth  melting,  and  tliat  it  then  rapidly 
deteriorate.  Tlio  commencing  breaking-weiglit  was  103  lbs., 
and  tins  went  on  inennsing  until  at  the  twelfth  melting  the 
breaking-weight  wu.s  7-!5  lb«.     At  the  thirtceutU  it  was  071  lbs. ; 


PROPERTIES   OP    CAST    IRON,  59 

at  the  fifteenth,  331  Ibj. ;  at  the  sixteenth,  3.J3  Ih.;.;  and  at  the 
seventeenth  melting  the  laltiiiiate  strength  was  33U  lbs. ;  or  less 
than  one-half  of  its  maximum  strength.  After  the  fourteenth 
melting,  the  molecules  of  the  metal,  when  fractured,  appeared  to 
have  undei'gone  a  decided  change.  There  was  a  bright  band, 
like  silver,  on  the  edge  of  the  bar,  whilst  the  middle  retained  the 
ordinary  crystalline  fracture;  and  in  the  succeeding  meltings,  the 
metal  was  bright  all  over,  resembling  the  fracture  of  cast  steel. 

Maintainutff  the  iron  infusion  for  shorter  or  longer 
pei'iods,  is  attended,  in  many  instances,  with  a  corresponding 
improvement  in  the  textile  strength  of  the  product.  By  keeping 
it  in  fusion  a  longer  period,  the  number  of  remeltings  necessary 
to  develop  its  maximum  strength  may  be  reduced.  In  the  case 
of  the  Manchester  experiments  referred  to,  the  iron  was  in  com- 
paratively small  quantity,  reduction  to  a  molten  state  took  place 
with  great  rapidity,  and  the  process  was  completed  in  a  very 
short  period,  the  American  experiments,  on  the  other  hand,  were 
made  on  several  tons  of  iron,  in  reverberatory  furnaces  ;  reduc- 
tion to  the  liquid  state  took  place  more  slowly,  and  the  entire 
process  lasted  several  hours.  The  gradual  reduction,  also,  of 
the  iron  and  its  flowing  to  the  hearth,  exposed  it  to  a  prolonged 
decarbonization,  and  resialted  in  a  corresponding  greater  purity, 
with  fewer  remeltings. 

The  iniproi^einent  in  quality  obtained  by  keeping  the 
iron  in  fusion  for  periods  after  deduction,  is  very  well  shown  by 
the  results  obtained  with  the  Stockbridge  iron  : 

Tensile  strength  in 

Ib.s.  per  eq.  in.      Density 

Iron  twice  remelted  and  cast  on  (^  1"  861  7  196 

reduction  to  liquidity.  j  . . . .    , 

"    maintained  in  fusion  1  hour 20,420   7.234 

2  "      24,383  7.270 

3  "      25,773  ....  7.283 

In  other  experiments  the  increase  of  density  and  tensile 
strength  is  equally  great,  and  shows  the  wide  field  for  improve- 
ment which  the  mere  ditference  in  mode  of  reduction  and  time 
of  casting  offers  to  the  consideration  of  the  practical  founder. 

Tenacity.  Density. 

Iron  in  fusion    ^  hour 17,843  7.187 

1       "      20,127   7.217 

"  "        ]|     "      24,387   7.250 

"  "        2       "      34,496   7.279 

The  several  trials  were  made  with  the  same  charge  of  iron,  but 
the  metal  for  testing  was  withdrawn  at  the  periods  named.  Ths 
composition  of  the  original  gray  pig-iron  doubtless  influences, 
in  a  very  great  measure,  the  amount  of  improvement  obtained 
with  difterent  periods  of  fusion.  A  refining  of  the  iron  takes 
place  ;  and  the  quantity  of  alloyed  matters  oxidized  and  re- 
moved, will  vary  with  the  character  of  the  pig-iron.  Carbon  is 
a  principal  ingredient  in  cast  iron  ;  and  a  long  exposure,  eq^ually 


60  PROPERTIES    OF    CAST   IRON. 

Avith  repeated  meltings,  offers  a  read)'  metUoiI  of  burning  it 
away.  The  reverberating  cohimn  of  gases  in  the  romelting 
furnace,  contains  a  portion  of  free  oxygen,  which  combines  with 
the  carbon  to  form  carbonic  acid  ;  but  since  the  oxygen  is  in 
contact  onlj'  with  the  surface  of  the  metal,  its  removal  requires 
numerous  fusions,  or  the  maintenance  in  fusion  for  a  long  period, 
llepeated  fusions  of  the  iron  ai-e  attended  with  a  heavy  waste  of 
material,  which  goes  far  to  compensate  for  the  increase  of 
strength.  In  the  experiments  at  Manchester,  the  maximum 
strength  was  attained  only  at  the  twelfth  fusion,  and  then  ex- 
ceeded the  original  strength  in  the  ratio  of  7'25  to  403.  This  in- 
crease, however,  was  oljtained  by  a  waste  in  remclting  of  more 
than  one-half  of  the  iron  originally  charged  ;  so  that,  in  a  com- 
ii.ercial  point  of  view,  a  casting  of  given  strength  prepared  from 
iron  remelted  this  number  of  times,  will  cost  nearly  twice  ns 
much  as  a  similar  easting  prepared  from  the  original  crude  iron. 

liy  e.rposiiif/  tlta  molten  ii'oil  io  the  white-hot  current 
of  gases  for  a  longer  ])eriod,  t'.:e  improvement  in  strength  is  ob- 
tained with  a  comparatively  small  waste  of  material.  Apparently, 
the  forcing  of  air  under  the  STirface  of  the  iron,  so  as  to  pervade 
the  entire  contents  of  the  hearth,  and  react  with  great  rajjidity 
on  the  alloyed  matters,  would  accomplish  the  refining  and  de- 
velopment of  strength  most  complet(dy  ;  but  in  practice  the  re- 
verse is  found  to  follow  this  treatment.  Combustion  of  a  portion 
of  the  iron  takes  i)lac>'  ;  and  the  newly-formed  oxide,  remaining 
to  a  certain  extent  amongst  the  i)arti(;les  of  iron,  reduces  its 
tenacity  below  that  of  the  original  crude  iron.  On  the  other 
hand,  the  exposure  of  the  reduced  iron  to  a  current  containing 
free  oxygen  results  in  the  rapid  dejirivation  of  carbon,  silicon, 
phosphorus,  snlpliur,  Ac;  the  first  in  a  gaseous  combination, 
the  rest  in  the  slag  produced  in  the  jiroc-ess.  Th<'  temperature 
of  the  molten  mass  in  the  hearth  is  une(pial,  and  subject  to 
slight  variations  ;  tlie  result  is  the  jn-oduction  of  numerous  slow 
curnaits,  which  successively  bring  the  entire  charge  of  metal 
under  the  refining  influence  of  the  passing  current  of  gases. 

Irons  conlaining  a  large  )>roportion  of  carbon,  relatively  to  the 
other  impurities,  are  most  susceptible  of  imi>rovement  by  treat- 
ing in  this  manner.  ^Vith  other  irons,  ]>re])arcd  with  a  heavy 
burden  of-  materials  on  the  blast-furnace,  the  improvement  is 
less  striking,  and  is  attended  with  a  larger  waste  of  metal  through 
oxidation. 

The  rnpulifi/  and  imtnner  cf  roolivy  the  rastiTiff 
directly  iniluencc's  the  tensile  strength  of  the  metal.  It  is  found 
that  Kinall  castings,  moulded  in  vertical  dry-sand  flasks,  have  a 
less  tinsile  strength  tlian  large  castings  similarly  mouMed,  and 
cast  from  the  same  cliarge  of  iron.  The  diminution  of  strength 
in  tlie  case  of  the  Hinall  bars  amounted  to  nearly  five  ]>er  ('ent. 
Tested  transvers(!ly,  however,  tlie  strength  of  the  metal  in  the 
Hiiiallcasting  was  to  that  of  the  metal  in  the  large  as  1,14')  to  1,000. 
This  ditrereiice  between  the  coiMi>arative  tensile  ami  transverse 
strengtliH  of  th(!  iron  from  Uw  two  castings  is  easily  ex])lained. 
The  rapid  cooling  of  the  small  bar  resulted  in  the  bIuu  attaining 


PROPERTIES   OP    CAST   IROJ^.  61 

great  hardness,  an,l  llie  metal  to  be  in  a  state  of  tension.  Tiiis, 
while  it  increased  the  transverse  strength,  reduced  the  ability  of 
the  iron  to  bear  a  direct  tensile  force.  The  large  casting  cooled 
slowly,  in  consequence  of  its  great  bulk  ;  and  the  heat  in  the  in- 
terior mass  having  to  j^ass  through  the  skin,  produced  a  partial 
annealing  of  this  portion.  Softened  in  this  miinuer,  it  was  less 
able  to  bear  a  transverse  strain  ;  but  the  equal  rate  of  contraction 
of  the  mass  was  favorable  to  the  resistance  of  tensile  force. 

TJie  tensile  streiiffth,  as  influenced  by  the  size  of  the 
masses  and  rapidity  of  cooling,  varies  with  the  condition  of  the 
iron  previous  to  casting.  If  the  refining  process,  by  lengthened 
fusion  or  numerous  remeltings,  be  carried  too  far,  the  resulting 
product  will  be  of  a  hard,  brittle  quality;  and  when  cast  into 
small  articles,  be  chilled  to  that  extent  as  to  be  incapable  of 
working  with  steel  cutting-tools.  Cast  into  larger  articles,  how- 
ever, and  cooled  more  slowly,  a  maximum  tenacity  may  be  de- 
veloped, and  the  texture  of  the  iron  be  found  of  a  character  to 
bear  cutting-tools  on  its  surface. 

Continuing  the  operation  too  long,  also  produces  a  thickening 
of  the  molten  iron,  until  it  is  of  too  great  a  consistency  for  the 
proper  tilling  of  the  mould,  and  the  prevention  of  air  cavities  in 
the  body  of  the  casting.  The  burning  av.'ay  of  the  carbon  is  at- 
tended with  a  loss  of  fluidity;  and  this  defect  occurring,  there  is 
no  remedy  short  of  introducing  further  portions  of  the  original 
crude  iron,  to  restore  by  mixing  a  certain  degree  of  fluidity. 
Thin  castings,  and  others  reqiiiring  great  sharpness  in  the  an- 
gles, can  be  successfully  made  only  when  the  iron  contains  a 
large  portion  of  the  carbon  contracted  in  the  blast-furnace. 
Freedom  fi-om  air  cavities  demands  the  emploj'ment  of  a  similar 
metal. 

Castltlfj  under  a  head,  or  considerable  pressure  of  the 
fluid  metal,  is  resorted  to  in  very  many  instances,  in  order  to 
obtain  great  solidity.  The  density  of  the  metal  is  increased,  at- 
tended with  a  corresponding  augmentation  of  tensile  strength. 
An  experiment  on  the  comparative  density  and  tenacity  of 
rough  pigs  cast  horizontally,  and  a  moulded  bar  cast  vertically, 
gave  the  following  results: 

Tenacity.     Density. 

Rough  pigs,  cast  horizontally 14,481 ....  T.OOt 

Bar,  cast  vertically   lG,42t. . .  .7.085 

In  all  close-flash  rasfblf/s,  the  head  of  metal  is  required 
to  be  several  inches  above  the  highest  point  of  the  mould,  or  the 
perfect  filling  may  not  be  insured.  Rollers  for  mill  machinery, 
and  numerous  other  articles,  are  frequently  cast  with  a  vertical 
pressure  of  two  or  three  feet  of  liquid  metal  above  the  most  ele- 
vated part  of  the  moul  1.  The  effects  of  atmospheric  pressure  on 
the  surfi\ce  of  the  liquid  iron,  while  cooling,  has  been  tried,  and 
apparently  produced  a  small  improvement  in  the  metal.  Fur- 
ther experiments,  however,  are  required  to  show  the  amount  of 
each  improvement  under  varying  pressures  of  blast. 


62  PROPERTIES   OF    CAST  IRON. 

Bij  the  rapid  cooling  of  castings  through  the  interven- 
tion of  water,  the  tensile  strength  of  the  metal  may  be  nearly  de- 
stroyed. The  unequal  rates  of  contraction  which  ensue,  bring 
into  play  forces  greater  than  the  cohesive  jiower  of  the  metixl  is 
able  to  witlistand.  A  similar  result  is  frequently  observed  in 
the  case  of  iron  cylinders,  cast  in  thick  iron  moulds,  with  the 
view  of  hardening  the  surface  of  the  casting,  especially  if  the 
metal  is  of  a  high  quality.  Fissures  running  nearly  parallel 
with  the  axis  of  the  cylinder  are  produced  on  its  surface,  and 
penetrate  a  short  distance  towar.l  the  centre.  Their  production 
is  a  result  of  the  rapid  cooling  of  the  skin  of  the  casting,  through 
the  absorption  of  caloric  by  the  mass  of  cold  iron  composing  the 
mould.  With  a  slow  and  gradual  cooling  of  the  entire  mass,  the 
skin  contracts  equally  with  the  rest ;  but  in  chilled  castings  it 
diminishes  in  diameter  more  rapidly  than  the  interior  of  the  in- 
candescent iron,  which  is  forced  out  of  the  mould  through  the 
head  while  yet  effectively  liqiiid;  but  immediately  solidification 
commences  in  the  interior,  the  skin  is  in  a  state  of  tension,  and, 
at  its  then  temperature,  a  direct  severance  in  one  or  more  places 
is  inevitable.  This  fracturing  of  the  skin  occurs  only  with  irons 
possessing  more  than  ordinary  hardness  previous  to  fusion;  but 
it  is  only  with  such  that  an  extremely  hard  surface  to  the  cylin- 
der can  be  obtained.  Hence,  the  greater  the  degree  of  hardness 
imparted  to  the  iron,  the  greater  the  liability  to  rupture  in 
cooling. 

These  considerations  point  to  the  impoi-tant  bearing 
which  the  manner  of  cooling  has  on  the  tensile  strength  of  cast 
iron.  The  circumstance,  that  a  very  rapid  cooling  is  frequently 
attended  with  a  direct  fracture  of  the  metal  before  the  casting 
has  left  the  foundry,  shows  the  very  great  attention  which  should 
be  paid  to  this  feature  of  the  process.  Unless  great  care  be 
taken,  the  best  pig-irons  may  be  so  weakened  during  cooling  as 
to  possess,  in  the  finished  Civsting,  a  tensile  strength  greatly  be- 
low that  of  very  inferior  irons  in  other  castings  cooled  on  correct 
principles.  Probably  in  a  majority  of  castings  the  quality  of 
of  the  original  pig-iron  has  less  to  do  with  the  ultimate  strength 
of  the  piece  than  the  mode  in  which  the  iron  is  treated  during 
and  after  fusion. 

When  cast  into  large  ina-ses  and  slowly  cooled,  some 
time  elapses  before  the  molecules  of  the  metal  arrange  them- 
selves into  the  position  offering  the  greatest  resistance  to  tensile 
strain.  The  experiments  made  were  confined  to  the  testing,  by 
repeated  firing,  of  heavy  ordnance,  with  various  intervals  of  time 
between  tlieir  manufacture  and  use.  Pieces  cast  some  years  be- 
fore testing  stood  several  times  the  quantity  of  firing  of  other 
pieces  cast  but  a  few  months  previously.  The  tensile  projierties 
of  the  metal  did  not  exjilain  the  diU'erence;  and  the  form,  <liinen- 
sions,  weight,  method  of  casting  and  cooling,  and  the  manner  of 
proving  were  the  same  in  all  the  pieces  tried.  Further  experi- 
ments on  this  remarkable  jjrojx-rty  are  required  to  show  the  sev- 
eral cireuinstanees  umler  wiiie.li  it  is  devehqied. 

The  tensile  strength  of  many  cast  irons  may  be  improved 


PROPERTIES    OF    CAST   IRON. 


63 


by  adding  to  them,  after  fasion,  but  previous  to  flowing  out  of 
the  remelting  furnace,  a  quantity  of  wrought  iron  in  a  divided 
state.  By  this  proceeding  the  strength  of  the  irou  may  be  in- 
creased to  nearly  fifty  i^er  cent,  over  that  of  the  original  pig. 
Since,  however,  the  numerous  experiments  made  in  America 
have  conclusively  shown  that  remelting  alone  will  produce  a 
much  greater  improvement  of  quality,  we  must  infer  that  the  in- 
crease of  quality  jDlaced  to  the  use  of  malleable  scrap  really  oc- 
curred from  the  remelting  ;  and  that  by  treating  the  iron  to  a 
prolonged  fxision,  greater  strength  woi;ld  have  been  produced 
without  the  use  of  the  scrap-iron. 


Kesistance  of  Cast  Iron  to  Compression. 

TJie  force  required  to  crush  ci/Iiuflertt  two  and  a  half 
times  their  length,  increases  with  the  hardness  of  the  iron,  when 
the  cooling  has  not  permanently  injured  the  structiire  of  the  iron. 

No.  1  foimdry  iron  required  a  force  of  119,650  lbs.  the  sq.  in. 

Nos.  1  and  3  mixed  "  "  168,589 

Nos.  1  and  2      "  "  "  152,560 

Nos.  1,  2,  and  3  mixed      "  "  160,803  "         " 

In  building  and  construction,  the  direct  crushing  force 
is  seldom  brought  into  action  to  that  extent  that  the  metal  is 
crushed  to  pieces.  Accidents  invariably  occur  from  the  lateral 
flexure  of  castings,  produced  through  a  deficiency  of  stiffness  in 
the  deflective  part. 

In  order  that  the  various  qualities  of  difi'erent  metals  may  be 
readily  compared,  and  that  the  variations  which  occur  in  each 
may  be  seen  at  one  view,  resiilts — collected  from  the  {^receding 
tables,  and  from  all  the  forms  in  which  the  several  metals  were 
tested— are  given  in  the  following  table  : 

Various  Qualities  of  Different  Metals. 


Density. 

T'liicity. 

rifinntp 
torsun. 

Coraprf,s'd 
SlreDgth 

nardni^ss. 

Cast  Iron 

J  Least. . . . 
j  Greatest. 

6  900 

9,000 

5,005 

84,529 

4.57 

7.400 

45,970 

10,467 

174,120 

33.51 

Wrought  Iron 

j  Least.. .  . 
(  Greatest. 

7.704 

7.858 

38,027 
74,592 

7,700 

40,000 
127,720 

10.45 
12. 14 

Bronze 

1  Loast  . . . 
j  Greatest. 

7.978 

17.698 

5,511 



4.57 

8. 9  "3 

56,786 

5  94 

Cast  Steel 

J  Least . .  . 
1  Greatest. 

7.729 
7.802 

128,66o 



198,944 
391,985 



This  table  shows  the  great  range  in  quality  of  the  cast  iron, 
wrought  iron,    bronze,   and   steel   operated   on.     By  judicious 


64  MANUFACTURE    OF   WROUGHT   IRON. 

treatment  the  tensile  strength  of  the  cast  iron  is  increased  so  as 
to  be  in  excess  of  much  of  the  wrought  iron  manufactured,  and 
nearly  two-thirds  of  the  strength  of  the  best  merchant  bar-iron. 
"With  cast  metal  of  this  (jnality,  the  manufactiire  of  malleable 
iron  ordnance  will  no  longer  be  a  desideratum. 


MAITUFACTURE    OF   WROUG-HT 

IRON. 


The  conversion  of  the  crude  cast  iron  of  the  high-b'ast  furnace 
into  the  malleable  iron  of  commerce,  is  essentially  a  succession 
of  relining  operations  for  the  separation  of  the  extraneous  matters 
combined  with  the  metal.  The  manner  in  which  this  is  accom- 
plished varies  in  different  districts,  and  is,  in  part,  influenced  by 
the  nature  of  the  alloyed  matter.  The  old,  and  hitherto  prefer- 
able process,  consists  in  exposing  the  molten  metal  to  currents 
of  blast  for  two  or  three  hours,  in  a  low  open  blast-furnace,  tech- 
nically termed  a  "refinery."  In  many  works,  reverberatory  fur- 
naces arc  e:iiploj-ed,  and  the  crude  metal  is  exposed  on  the  cen- 
tral bed  to  the  action  of  a  highly-heated  column  of  gas  from  the 
fire-place,  for  about  an  hour  and  a  half.  Several  of  the  French 
and  American  manufacturers  employ  the  open  charcoal  forge, 
similar  in  construction  to  the  Catalan  hearth  already  described. 
It  may  bo  remarked,  however,  that  wb.atever  construction  of  fur- 
nace be  employed  for  the  jiurpose,  atmospheric  air  is  the  princi- 
pal agent  emploj'ed  in  purifying  the  crude  iron. 


The  Blast  Refining  Furnace 

Is  built  near  the  blast-furnace,  from  whence  the  liquid  iron  flows 
direct  into  the  hearth  of  the  fire.  It  consists  of  a  cast  iron  frame- 
work, surmounted  by  a  brick  chimney;  at  the  bottom  is  a  shal- 
low, quadrangular  hearth,  into  which  dip  the  tuyeres  of  two  or 
more  blast-pipes.  The  sides  of  the  liearth  are  formed  of  hollow 
cost  iron  blocks,  through  which  water  circulates  to  keep  them 
from  fusing  with  the  high  temperature,  while  the  bottom  is  of 
refractory  sandstone.  In  front  is  a  cast  iron  dam-plate,  furnished 
with  a  tapping  hole  for  withdrawing  the  nfmed  metal;  the  inner 
side  being  jjrotected  with  brick  or  clay  lining.  A  shallow  mould, 
formed  of  tliick  cast  iron  blocks,  partially  suspended  in  a  cistern  of 
running  water,  is  placed  in  front  of  a  dam  plate,  to  receive  the 
charge  from  the  heartli;  water  also  circulates  in  the  tuyeres,  to 
j)revent  their  lower  extremities  from  burning.  The  blast  is  ad- 
initteil  l)y  a  large  i)ipe  to  the  valve-box,  from  which  its  escape  to 
the  blast-nozzle  is  regulat<'d  by  a  closely-fitting  stop-valva  A 
single  refinery,  or  one  blowing  from  one  side  only,  will  have  a 
licarth  about  three  fct  sqnar(!  in  the  inside  by  eighteen  inches 
deep;  a  double  refinery,  or  ono  blown  from  two  sides,  has  a 


M'NUFACrUEE    OF   WROUGHT   IRON.  65 

hearth  about  four  feet  square  and  twenty-one  inches  deep,  with 
pipes  about  an  inch  and  a  lialf  bore  at  the  point. 

The  v< fining  o/  the  crude  iroii  is  conducted  somewhat 
in  the  foliowin<^  manner  :— The  hearth  is  tilled  with  coke,  and 
the  blast  partially  applied,  until  the  interior  has  attained  a  high 
temperature.  If  working  on  cold  iron,  a  quantity  of  pigs,  weigh- 
ing from  twenty  to  thirty  per  cent,  arj  thrown  in  on  the  in- 
candescent fuel,  and  covered  with  additional  coke.  The  full 
blast  is  now  applied,  and  the  fire  urged  so  as  to  attain  an  inten.se 
heat  ;  additional  fuel  being  added  as  required  until  the  pigs  of 
iron  soften,  and  gradually  fusing,  fall  through  the  interstices 
formed  by  the  coke  to  the  bottom.  By  means  of  iron  bars,  the 
attendant  keeps  theinfu.sed  portions  of  metal  under  the  intiuence 
of  the  heat  around  the  tuyeres  ;  and,  finally,  stirs  up  the  con- 
tents of  the  hearth,  to  insure  the  perfect  reduction  of  the  entire 
charge.  When  the  entire  charge  has  been  collected  on  the  bot- 
tom of  the  hearth,  the  refining  process  may  be  said  to  commence. 
The  union  of  the  oxygen  of  the  blast  with  the  solid  carbon  com- 
bined with  the  metal,  results  in  such  a  rapid  evolution  of  gaseous 
carbon,  that  the  mass  spontaneously  boils  up,  rising  several 
inches  :  the  superincumbent  stratum  of  fuel  rises  also,  and 
vibrates  with  the  movement  of  the  boiling  metal,  while  inniimer- 
able  minute  globules  of  oxidized  iron  are  thrown  out  of  the 
chimney.  Considerable  skill  is  required  in  managing  the  blast 
to  a  successful  issue.  The  angle  at  which  the  pipe  dips  into  the 
hearth  appears  to  be  of  importance  to  the  process  ;  each  refiner, 
however,  works  his  blast  according  to  his  own  judgment.  The 
several  portions  of  the  charge  are  successfully  brought  under  the 
oxidizing  influence  of  the  blast,  so  as  to  be  equally  acted  upon, 
until  the  major  portion  of  the  carbon  being  disengaged,  indicates 
the  approaching  completion  of  the  process.  The  fire-clay 
"  stopping ''  of  the  dam-plate  is  now  removed,  and  the  metal  and 
cinder  allowed  to  flow  into  the  shallow  moiild  in  front.  "When 
collected  in  the  mould,  the  water  is  thrown  rapidly  over  it,  cool- 
ing the  siirface  i^ortions,  and,  at  the  same  time,  oxidizing  a  por- 
tion of  the  iron.  The  cinder,  by  its  inferior  specific  gravity, 
separates  itself  from  the  metal,  rising  to  the  top,  in  which  it  is 
partially  assisted  by  the  attendant  beating  the  molten  mass  with 
an  iron  bar.  On  the  first  application  of  water,  the  steam  pro- 
duced lodging  in  the  viscid  cinder,  swells  it  up  several  inches  ; 
this  is  broken  down  by  the  beating  as  fast  as  it  rises,  in  order 
that  the  water  may  the  more  readily  reach  the  lower  portions. 

When  cold,  the  plate  of  refined  iron,  which  may  be  about 
three  inches  thick  by  three  feet  vn.^e,  is  removed  by  a  carnage 
to  the  bank,  where  it  is  broken  into  pieces  of  a  size  convenient 
for  the  succeeding  operation  of  puddling.  The  fracture  of  good 
metal  exhibits  a  silvery  whiteness,  while  that  of  inferior  kinds  is 
perceptibly  duller.  On  the  surface  it  is  rough,  and  covered 
witli  irregular  cavities,  to  which  the  name  of  hnnej^comh  has  been 
given  from  some  fancied  resemblance  to  that  substance.  The 
depth  of  this  cellular  structure  varies  with  the  quality  of  the 
metal  and  length  of  blowing,  being  least  in  the  best  irons  with  a 
limited  blowing. 


66  MANUFACTURE   OF  WROUGHT   IRON. 

Ttie  cheiuival  effects  of  the  blowing  are  not  well  under- 
stood, researches  into  the  several  reactions  which  take  place  in 
the  hearth  having  been  almost  wholly  neglected.     By  carefully 
analyzing  the  resulting  hue  metal  and  its  accompanying  cinder, 
and  comparing  the  results  with  the  analyses  of  crude  iron  and 
cinder,  some  light  was  thrown  on  the  subject,  which,  pending 
the   compietion   of  extensive    exp»nmeutal    researches   now   in 
progress,  the  author  would  sum  up  as  follows  : — The  metal  and 
cinder  together  represent  the  crude  iron,  with  oxygen  derived 
from  the  blast,   and  solid  matters   derived  from  the  fuel  :  the 
quantity  of  matter  derived  from  the  material  on  the  hearth  is 
too  inconsiderable  for  remark  here.      Refinery  cinder  contains  a 
large  percentage  of  silica,  which  must  have  been  derived  prin- 
cipally from  the  iron  ;    it  also   contains    protoxide  of  iron  to  a 
large  amount,  from  the  same  source  ;  phosphoric  acid  is  a  con- 
stituent to  the  extent  of  three  or  four  \>er  cent,  in  some  speci- 
mens ;  sulphur  is  a  common  ingredient,  but  may  have  been  de- 
rived in  part  from  the  fuel.     Manganese,  magnesia,    and   lime 
exist  in  small  (quantities  ;    alumina  to  the  extent  of  five  or  six 
per  cent.     After  deducting  the  ash  of  the  fuel  and  the  protoxide 
of  the   iron,   there  remains  a   considerable  quantity   of  earthy 
matters,  the  presence  of  which  can  only  be  accounted  for  on  the 
supposition  that  they  have  been  derived  from  the  crude  iron, 
and  that  to  this  extent  the  cast  iron  has  been  purified  of  alloys. 
l*inl(llinf/  the  rcjiixil   nnfal. — The  further  rtfinement 
of  the  iron   fnnn   the  blast    rctining-furnace  is  conducted  in  re- 
verberatory  furnaces,   technically   termed  "  puddling-furnaces," 
in  which,  by  skilful  manipulation,  it  is  deprived  of  most  of  the 
remaining  alloy.     The  puddling-furnace  consists  of  a  rectangxa- 
lar  erection  of  iron  plates,  nearly  six  feet  high,  the  same  distance 
between  the  two   sides,  and    twelve  feet  long,  lined  throughout 
with  fire-brick.     At  one  end  is  a  fire-place  aboiit  three  feet  square  ; 
divided  from  the  fire  by  a  brick  bridge  is  the  body  of  the  furnace, 
six  or  seven  feet  long,  and  three  and  a  half  feet  wide  at  its  widest 
part,  resting  on  a  cast  imn  bottom-jjlate,  on  a  'evel  nearly  with 
the  bars  of  the  fire-place  ;  the  farthest  end  of  the  furnace  is  con- 
tracted   to   eighteen    inches    in    width,    where   it  joins   a  brick 
chimney  thirty-five  to  forty  feet  high,  furnished  witli  a  damper 
at  top.     The  fur  'ace  is  arched  over  with  fire-brick  ;  and  to  pre- 
vent the  sid(!S  from    being   thrust   out  by  the  exjansinu  of  the 
heated  bricks,  a  number  of  stout  wrought-iron  bolts  ef)nn(  ct  the 
two  si  le- plates,  which  receive  the  thrust  of  the  arch.     At   one 
side  of  the  })odv  a  working-door   is  jilaced,  in  a  stout  cast-iron 
frame  ;    the  bottom  eight  or  ten  inches  above  the  iron  bottom  of 
the  fiirnao'.     The  door  is  moved  vertically  by  a  balanced  lever, 
the  inner  side  fitted  with  a  brick  protecting  lining,  and  is  f\ir- 
ni8he<l  at  bottom  with  a  small  notch,  for  the  insertion  of  the  iron 
bars  used  during  the  operation.     The  fire-jdace  has  a  small  lat- 
eral opening  for  charging  fuel,  which  is  afterward  stopped  by  a 
large  piece  f>f  coal.     The  cinder  ])rodiiee(l  during  tlie  i)ud(lling 
procress  flows  over  a  small  bridgf^  in  tlie  flue,  and  through  an 
opening  in  the  bottom  of  the  stack  to  the  outside      To  maintain 


MANUFACTURE    OF    WROUGHT   IRON.  67 

the  stream  of  cinder  sufficiently  liquid  for  running,  a  small  coal- 
fire  is  maintained  at  the  foot  of  the  chimney,  from  whence  the 
cinder  flows  into  a  receptacle  provided  for  the  purpose. 

The  cast  iron  bottom-plate  is  supported  at  short  intervals  by 
cross-bearing  bars  and  pedestals;  air  is  allowed  free  access  to  it 
from  below.  Indeed,  without  this  precaution,  the  bottom  would 
be  imme;liately  fused.  Occasionally  a  portion  of  the  brick-work 
of  the  side  of'  the  furnace  next  the  body  or  working  part  is  re- 
moved, and  cast  iron  blocks,  cooled  by  a  current  of  air  or  water, 
substituted. 

Ansnmim/  that  a  charge  has  been  withdrawn  from  the 
liot  furnace,  the  process  is  recommenced  by  charging  through 
the  furnace  door  a  quantity  of  refined  metal,  broken  into  small 
pieces:  from  four  to  five  cwts.  constitute  a  charge.  The  pieces 
of  metal  are  evenly  distribiated  over  the  bottom  as  far  as  practi- 
cable in  an  inclined  position,  the  door  shut,  and  a  little  dust 
thrown  around  its  edges  to  exclude  the  cold  air.  Attention  is 
now  directed  to  the  fire,  which  should  be  cleaned,  fresh  fuel 
added,  and  the  damper  f  ally  opened,  to  allow  of  an  intense  heat 
being  generated  in  a  few  minutes.  The  edges  of  the  pieces  of 
metal  soon  attain  a  white  heat,  and  begin  gradually  to  soften  ; 
the  portion  of  the  charge  against  the  fire-place  attaining  a  melt- 
ing temperature.  The  "puddler,"  as  the  attendant  workman  is 
called  with  a  stout  i  on  bar  inserted  through  the  notch  in  the 
door,  lifts  u^j  the  coldest  pieces  and  pushes  them  forward  into 
the  hottest  parts  of  the  furnace,  until  the  whole  is  nearly  dis- 
solve! into  a  liquid  mass.  When  a  portion  of  the  iron  has  been 
melted,  the  hooked  bar  is  inserted  and  the  entire  mass  raked  up 
and  exposed  to  the  reverberating  action  of  the  hot  gases  from  the 
fire.  At  this  stage,  the  inside  of  the  furnace  presents  a  scene  of' 
intense  brightness,  and  an  inexperienced  eye  is  finable  to  dis- 
tinguish the  metal  through  the  dazzling  whiteness  of  the  whole 
of  the  interior.  Through  the  small  notch  in  the  door,  the  pud- 
dler conducts  the  operation  by  constantly  raking  up  the  fluid 
iron,  in  order  that  the  gases  of  the  reverberatory  current  may 
play  on  the  whole,  thus  lifting  from  the  bottom  any  portions 
that  may  have  set  through  lowness  of  temperature  Since  the 
current  has  no  power  to  penetrate  the  liquid  iron,  and  thiis  com- 
bine with  the  carbon  and  other  alloyed  matters,  as  in  the  blast- 
refinery,  the  i^ud.ller's  principal  diity  is  to  mechanically  agitate 
the  particles,  so  that  every  portion  may  be  successively  brought 
in  contact  with  the  free  oxygen  in  the  current.  The  assistant 
pud  Her  attends  to  the  fire,  which  he  maintains  in  full  activity; 
at  other  times  he  relieves  his  partner,  or  works  in  conjunction 
with  him.  After  some  time  thus  occupied,  the  puddler  will  have 
separated  the  larger  portion  of  the  alloyed  matters  from  the  iron, 
and  brought  it  to  that  point  technically  known  as  "coming  to 
nature."  When  this  is  the  case,  the  metal  is  seen  to  attain  con- 
sistence, and  a  curdy-like  matter  is  collected  by  the  hooked  bar; 
this  rapidly  augments,  iintil  a  sufficiency  has  been  collected  to- 
gether to  form  a  ball  or  bloom.  A  second,  third,  fourth,  and 
fifth  collection  is  successively  made  and  placed  aside  in  the  fur- 


G8  MANUFACTURE    OF   WROUGHT   IRON. 

nace.  The  churge  of  refined  metal  will  thus  have  been  converted 
into  five  portions,  but  some  workmen  divide  it  into  seven  or 
eight.  While  collecting  the  metal  into  balls,  a  somewhat  lower 
temperatxire  prevails  ;  but  immediately  tliey  are  formed,  the 
damper  is  again  opened,  and  the  heat  of  the  furnace  forced,  so 
as  to  rapidly  agglutinate  the  particles  of  metal  in  the  balls.  Dur- 
ing the  raking  and  stirring  of  the  tinid  iron,  the  door  is  wedged 
fast  in  the  frame,  for  which  purpose  the  latter  requires  to  be 
made  very  strong.  The  securing  of  tlie  door  is  especially  requi- 
site in  forming  the  blooms,  since  with  the  heavy  hooked  bar  it 
aflbrds  the  puddler  an  excellent  fulcrum  for  compressing  and 
hugging  the  bull,  to  expel  as  much  as  possible  of  the  cinder,  and 
at  the  same  time;  give  it  a  favorable  form  for  yield.  The  forma- 
tion of  the  balls  completed,  the  damper  is  lowered  and  the  door 
opened;  they  are  now  withdrawn  and  conveyed  to  the  squeezer 
or  hammer,  for  compression  into  oblong  blooms.  The  yield  or 
produce  of  blooms  will  amoiint  to  nearly  ninety-five  per  cent,  of 
the  metal  charged — the  consuiniition  of  coal-fuel  averaging  in 
weight  one-half  as  much  as  that  of  the  blooms  produced. 

JL  superior  crouinuij  of  fuel  is  obtained  by  lengthening 
the  body  of  the  furnace,  so  as  to  admit  of  the  succeeding  charge 
being  placed  on  the  part  of  the  bottom  adjoining  the  stack  some 
time  before  the  charge  under  operaticm  is  withdrawn.  In  this 
way  the  new  charge  is  heated  to  redness  without  serious  detri- 
ment to  (ho  charge  in  covirse  of  being  balled  up,  .and  a  considera- 
ble saving  of  time  and  fuel  is  effected.  The  furnace  produces 
nearly  one-fourth  more  blooms,  with  tlic  same  daily  consumption 
of  fuel,  by  this  process.  Economy  of  time  and  fuel  is  still  fur- 
ther increased  by  drawing  the  supply  of  refiniul  metal  direct 
from  the  fining  hearth  in  a  fluid  state — the  fuel  and  time  ex- 
pended in  melting  the  iron  being  thereby  saved.  This  mode  of 
working,  liowever,  has  not  been  extensively  adopted,  difficulties 
having  been  met  with  in  effectually  separating  the  refined  iron 
from  its  accompanying  cinder. 

The  refinimj  of  rriidc  iron  in  the  reverberatory  furnace, 
embraces  in  one  furnace  the  separate  oi)erations  of  refining  and 
puddling.  In  dimensions  and  general  arrangements,  the  fur- 
naces employed,  known  in  the  trade  as  "boiling  furna(5es,"  are 
very  similar  to  ])Uildling-furnaces.  The  charging  and  first  ])art 
of  melting  are  similarly  conducted  in  both  j)rocesst's;  but  after 
the  fusion  of  the  crude  iron  on  tlio  bottom  of  the  furna(^e,  tiio 
appearances  presenti'd  are  very  dissimilar  to  those  witii  refincul 
metal.  At  first  the  licjuid  iron  forms  a  level  sheet,  which  grailu- 
ally  swells  up  with  the  rapid  mani|)ulation  of  the  workman,  until 
it  has  risen  six  or  seven  inelies  abovi^  its  former  level.  The  en- 
tire mass  ap])(!ars  to  heave  and  boil;  iniiuiuerabhi  erui)(ions  arise 
on  its  surface  and,  bursting,  discliarge  tlieir  ])ent-up  gases.  The 
jiuddler  must  bi;  incessant  in  liis  luaiiipulatioiis;  every  ))fn-t ion 
is  to  be  raked  up  and  ex]n)sed  to  tlie  oxidizing  influences  of  the 
current  of  the;  gases,  until  the  diininislied  action  siiows  the  near 
comjiletion  of  Mio  refining  i)art  of  the  process.  At  this  stage  a 
careful  manipulation,  with  a  judicious  regulation  of  the  temper- 


MANUFACTURE   OF   WROUGHT   IRON.  69 

ature,  results  in  tbc  segregation  of  the  iron  into  particles  of  a 
pasty  consistence,  which  eventually  agglutinate  by  pressure  into 
masses  of  the  required  size  for  blooms.  The  conclusion  of  the 
process,  the  drawing-out  of  the  blooms  and  recharging,  difl'ers 
from  this  part  of  the  puddling  process  only  in  the  tai)ping  oft"  the 
larger  portion  of  the  cinder  produced  previous  to  recharging. 

The  risintj  of  the  molten  mass  appears  to  result  from 
the  expansive  action  of  the  recently-formed  gases  against  the 
viscid  cinder.  By  attention  to  the  temperature  and  consistence 
of  this  cinder,  the  rising  may  be  partly  controlled;  but  the  nature 
and  quantity  of  the  alloyed  matters  greatly  influence  the  process. 
Since  the  carbon  combined  with  the  metal  has  to  be  eliminated, 
by  first  converting  it  into  carbonic  acid,  a  greater  or  less  amount 
of  carbon  will  resiilt  in  a  corresponding  rising,  and  lengthened 
manipulation,  for  its  exposure  to  the  oxygen  of  the  reverberating 
column  from  the  fire-place.  Iron  containing  a  maximum  per- 
centage of  carbon,  with  a  deficiency  of  earthy  matters  in  alloy, 
is  refined  with  difficulty;  and  requires  an  addition  of  cinder 
from  the  mill-rollers,  to  protect  the  metal  from  a  too  rapid  oxi- 
dation. Crude  iron  of  this  character  also  works  hot  in  the  fur- 
nace, and  great  difliculty  is  met  with  in  bringing  it  to  the  ag- 
glutinative point  for  balling  iip.  This  probably  arises  from  the 
heat  evolved  by  the  combustion  of  the  excessive  percentage  of 
carbon  in  the  crude  iron.  "Where  the  quantity  of  carbon  is  large, 
as  in  Scotch  irons  smelted  from  carbonaceous  ores,  the  heat  thus 
evolved,  with  an  ample  supply  of  air,  is  sufficient  to  raise  the 
temperature  to  a  degree  injurious  to  the  successful  manipulation 
of  the  iron,  and  dangerous  to  the  metal  bottom.  Throughout 
the  process,  also,  the  temperature,  from  the  same  caiise,  is  less 
under  the  control  of  the  workman. 

VtirloHS  hiveiltiOilS  have  been  tried  as  auxiliaries  for  the 
more  perfect  separation  of  the  matters  in  alloy,  but  very  few  have 
stood  the  test  of  experience.  The  application  of  steam,  at  one 
time  promised-  to  be  an  essential  improvement.  High-pressiire 
steam  was  conveyed  in  pipes  to  the  bottom  of  the  molten  iron  in 
the  blast  or  reverberatory  refining-furnace,  and  in  ils  escape  up- 
ward agitated  the  iron,  thereby  increasing  the  surface  exposed 
to  the  action  of  the  air  in  the  gaseous  current  from  the  fire-place. 
The  white-hot  iron  decomposed  the  steam  into  its  elements  of 
oxygen  and  hydrogen;  a  portion  of  the  former  reacted  on  the 
carbon  in  the  mass,  producing  carbonic  acid,  while  the  latter  was 
free  to  combine  with  any  sulphur  present.  With  some  irons,  the 
increase  of  temperature  on  the  combustion  of  the  carbon  was 
considerable,  and  greatly  expedited  the  operation.  Theoreti- 
cally, it  seemci  that  the  use  of  perfectly  dry  steam  should  leave 
little  to  beeflfected  in  the  way  of  refining  crude  iron;  and  the  fact 
of  the  invention  having  been  repatented  five  or  six  times  within 
the  last  few  years,  shows  that  much  attention  is  directed  to  it. 
Nevertheless,  the  use  of  steam  has  been  abandoned  in  the  works 
where  first  tried,  and  the  realization  of  the  theoretical  advantages 
is  still  a  desideratum,  Mr.  Nasmyth,  who  last  tried  the  experi- 
ment, having  come  to  the  conclusion,  after  many  experiments, 


70  MANUFACTURE   OP   WROUGHT   IRON. 

that  the  steam-condenser  had  the  effect  of  reducing  the  tempera- 
ture of  the  metal  in  the  furnace. 

The  sepdrafion  of  the  alloyed  nuttfers  has  also  been 
attem{3te  1,  by  adding  in  the  refining  process  various  substances, 
singly  or  in  mixture.  One  of  these  mixtures  consists  i)riueipally 
of  oxide  of  manganese  with  charcoal,  plumbago,  and  nitrate  of 
potash  In  a  second  mixture,  the  ingredients  were  tap  cinder, 
hematite  ore,  coke  dust,  fire-clay,  and  chalk;  a  third  was  com- 
posed of  sulphur,  nitrate  of  potash,  potash,  borate  of  soda,  and 
suljihate  of  alumina;  a  fourth  consists  of  jjeroxide  of  manganese, 
common  salt,  and  potter's  clay.  These  and  other  patented  com- 
positions, however,  have  not  answered  m  practice.  Ground  hem- 
atite, nearly  free  from  silicious  matter,  added  in  small  quanti- 
ties at  a  time,  facilitates  the  puddling  operation,  as  also  do  rich 
oxides  generally;  but  it  is  essential  that  they  be  free  from  dele- 
terious substances. 

Th4i  re/inin(f  of  the  iron  by  the  decomposition  of  water, 
has  also  been  several  times  attempted.  This  is  done  by  pouring 
the  liquid  iron  into  a  quantity  of  water  sufficiently  large  to  pre- 
vent the  iron  heating  it  above  the  boiling  point.  The  white-hot 
iron,  falling  in  finely  divide  I  streams,  decomposes  a  portion  of 
the  water,  liberating  oxygen,  which  reacts  on  the  carbon;  the 
hydrogen,  similarly  set  free,  acts  on  the  sulphur,  thus  forming 
sulpliureted  hydrogen.  Cold  iron,  immersed  in  water,  appears 
to  slowly  undergo  a  similar  alteration  of  composition;  but  in  this 
case  a  portion  of  the  metal  is  oxidized.  The  invention  is  a  very 
old  one,  having  been  used  more  than  half  a  century  ago.  It  was 
recently  male  the  subject  of  a  patent,  which  a  pi-ofessor  of  met- 
allurgy, in  his  inaugural  address,  adduced  as  a  striking  instance 
of  the  ignorance  prevailing  among  manufacturers.  Chemically, 
however,  the  discharging  the  iron  into  water  is  a  valuable  in- 
vention; while,  practically,  the  odor  of  sulphureted  hydrogen, 
evolved  during  the  pouring  of  sulphury  irons,  is  too  apparent  to 
doubt  the  good  effect  produced  on  the  quality,  when  the  opera- 
tion is  properly  conducted. 

The  refining  of  iron  in  reverbcratory  furnaces,  is  sometimes 
practised  on  tlio  liipiid  metal  run  direct  from  the  blast-furnace. 
A  saving  of  fuel  results  from  this  procedure,  and  the  quality  ap- 
pears to  be  slightly  improved  when  skilfully  conducted.  It  ne- 
cessitates the  erection  of  the  reverbcratory  furnace  and  forge 
close  to  the  blast-furnace,  which  is  a  disadvantage  iu  the  majority 
of  works,  and  leads  to  a  temperature  in  tlic  forge  almost  unen- 
durable. 


Shingliug  Puddlo-Balls. 

The  white  hot  lialls  of  the  i)uddling-furnaco  are  removed  to  the 
hammer,  to  be  furtln  r  shaped  before  passing  through  thiuoUers. 
The  forgc-lmiumer  or  helve,  is  usually  of  a  T  form  nn  th<!  plan, 
resting  at  each  wing  on  cast-iron  i)illars,  fixeil  in  jtomlerous  stan- 
dards, an  I  liftel  at  the  narrow  end  by  jjrojecting  cams  fixf^l  in 
a  cast-iron  ring  pi(!co,  which  receivesj  n  revolving  motion  from  a 


MANUPACTUEE   OF    WROUGHT   IRON.  71 

steam-engine,  or  other  motive  power.  The  anvil  is  fixed  in  a 
massive  iron  block,  weighing  several  tons,  situate  between  the  cam- 
ring  and  helve  standards.  The  hammer  is  a  loose  piece  of  iron 
fixed  in  a  socket  in  the  helve.  When  not  in  operation,  it  is  prop- 
ped up  at  a  distance  above  the  anvil,  and  beyond  the  reach  of  the 
cams  in  their  revolution.  The  entire  apparatus  rests  on  a  stout  iron 
bed-plate,  which  is  firmly  spiked  down  to  a  ponderous  wooden  bod- 
ding,  employed  for  the  purpose  of  reducing,  as  much  as  jDracti- 
cabie,  tUe  injury  which  results  from  the  vibration  of  the  blows. 

TiiC  haininev-nmii  takes  hold  of  the  hot  puddle-ball,  and 
lifting  it  on  the  anvil,  allows  the  hammer  to  fall  on  it  a  few  times, 
giving  it  a  turn  between  each  blow  to  approximate  it  to  the  square 
or  cylindrical  form,  as  may  be  desired.  He  then  skilfully  raises 
it  on  end  ;  .and  allowing  the  hammer  to  give  it  a  couple  of 
blows  in  this  direction,  completes  the  "upsetting,"  as  it  is 
technically  termed,  and  again  jjroceeds  to  the  reduction  of  the 
bloom  to  a  short  bar  five  or  six  inches  in  diameter.  The  efi"ect 
of  the  severe  hammering  is  to  expel  a  large  quantity  of  the  cinder 
wrapiied  up  with  the  iron  in  the  porous  puddle-ball,  and  by  con- 
densing the  particles,  otherwise  improve  the  quality  of  the  pro- 
duct. Hammering  each  ball  lasts  twenty-five  or  thirty  seconds, 
in  which  time  it  may  receive  thirty  or  forty  blows.  To  keep  the 
anvil  cool,  and  prevent  the  adhesion  of  cinder,  a  small  stream  of 
water  is  occasionally  directed  on  it.  The  still  red-hot  bloom  is 
taken  direct  to  the  roughing  rollers  of  the  puddling  train,  and 
rapidly  rolled  down  to  a  bar. 

The  forgc-Jianiiner  has  been  nearly  supplanted  by  the 
squeezer,  a  modern  contrivance  of  some  merit.  It  consists 
essentially  of  a  j^onderous  cast-iron  lever,  vibrating  on  centre 
gudgeons,  and  wrought  by  a  connecting-rod  attached  to  the 
crank,  placed  on  a  level  with  the  puddling-roUers.  The  under 
surface  of  one  end  carries  a  hammer  face  ;  underneath  this  is 
fixed  to  the  massive  frame- work  of  the  apparatus  a  long  and 
somewhat  broad  anvil-block  :  both  hammer  and  anvil  are  kept 
from  burning  out  by  a  stream  of  water  circulating  through  them. 

The  redaction  of  the  ball  to  a  cylindrical  bloom  in  the 
squeezer,  is  jjerformed  by  a  series  of  squeezings  ;  but  as  the 
stroke  given  to  the  lever  by  the  crank  is  invariable,  the  space 
between  the  hammer  and  anvil  regularly  diminishes  toward  the 
fulcrum.  In  the  jjrocess  of  squeezing,  the  bloom  is  rolled  over, 
at  each  stroke  of  the  lever,  by  a  movement  of  the  tongs,  to  the 
narrow  part,  until  the  required  diminution  of  size  has  been 
efi"ected.  The  upsetting  is  performed  at  the  extremity  of  the 
lever,  where  the  stroke  and  space  together  afford  ampie  height 
for  the  bloom  endwise.  Care  is  required  on  the  jsart  of  the 
shingler,  that  the  ball,  if  hard,  is  not  rolled  toward  the  fulcrum 
too  rapidly  ;  for  if  this  should  occur,  the  apparatus  must  give 
way  in  some  part. 

Lever  squeezers,  in  their  turn,  have  to  compete  with 
numerous  inventions  professing  to  perform  the  blooming  of  the 
ball  better  and  at  a  cheaper  rate.  Few  of  them,  however,  have 
been  able  to  stand  a  preliminary  trial  ;  and  even  those  invented 


1)^  MANUFACTURE   OF   WllOUGIIT  IRON. 

by  practical  iron-masters  Lave  liad  to  succumb  to  the  commoA 
squeezer  and  hammer.  The  cost  of  blooming  by  either  of  these 
apparatus,  in  a  well-arranged  forge,  working  to  its  full  power, 
amounts  to  only  ten  cents  per  ton,  including  interest  on  cai>ital 
and  repairs.  In  devising  a  substitute  for  either,  it  is  nece.ssarj' 
to  bear  this  item  in  mind  ;  for  it  is  very  evident  that  an  apparatus 
which  works  at  a  higher  rate  cannot  successfully,  in  a  commer- 
cial point,  compete  with  its  cheaper  rival. 

2he  steam-liannner  has  likewise  been  pressed  into  the 
service  of  the  iron  manufacturer.  This  apparatias  answers 
admirably  the  varyiogworkof  the  engine-maker  and  millwright ; 
but  for  iron-making  purposes  it  possesses  no  superiority  over  the 
common  forge-hammer,  though  several  times  more  costh'.  The 
balls  of  porous  iron  trom  the  piiddler  are  so  nearly  alike  in  size 
and  hardness,  that  little  variation  is  required  in  the  blows, 
which  the  common  hammer  gives  with  great  rapidity. 


Kolling  the  Bloom. 

TJic  hlo<»ti  from  the  hammer  or  squeezer  is  passed  first  be- 
tween a  i)air  of  roughing-rollers  (in  Staffordshire  they  are  called 
"bolting-rollers"),  and  then  between  a  pair  of  finishing-rollers, 
to  convert  it  into  a  flat  bar.  The  two  pairs  of  rollers,  and  their 
connecting  spindles,  pinions,  frames,  and  appendages,  are 
technically  called  a  "train."  Commonly,  the  rollers  are  sixteen 
or  eighteen  inches  diameter,  and  three  or  four  feet  long,  with 
end  bearings  nine  or  ten  inches  diameter,  and  stpiare  or  fluted 
projecting  ends,  by  which  they  are  driven.  Tiny  are  cast  of 
tolerably  hard  iron,  and  turned  in  a  lathe  to  the  required  longi- 
tudinal section.  Very  strong  pinions  couple  together  top  and 
])ottom  rollers,  so  as  to  deliver  the  iron  simultaneously  in  the 
same  direction.  The  cast  iron  frames  require  to  be  exceedingly 
massive,  and  substantially  fitted  with  adjusting  screws  and  nuts. 
At  one  end,  the  train  of  rollers  is  connected  to  a  prime-mover 
(generally  steam),  by  wliieh  they  are  driven  at  the  rate  of  sixty 
or  eighty  revolutions  per  minute.  The  ineiiualities  of  motion, 
■which  otherwise  would  be  very  great,  are  met  by  a  ]ion<lerous 
fly-wheel,  revolving  with  the  same,  or  even  greater  rai)idity  than 
the  rollers. 

T/ir  bloom  is  first  passed  through  the  largest  groove  ;  it  is 
then  lifted  buck  over  the  top  rolh'r,  turned  one  (piarter  around, 
and  ])iissed  tlimugli  tlu;  mxt  siiiidier ;  repeating  tho  jjrocess 
until  it  is  reduced  to  a  S(piare  bar,  sulliciently  siiiidl  for  entering 
the  rtiit  groovi-s  of  th(i  finisliing-rollers.  In  the  finishing  jiair  of 
rollers,  a  repetition  of  tho  rolling  and  returning  ndtices  it  to  tho 
rerpiired  thickness,  wlien  it  is  delivered  as  a  puddle-bar.  From 
first  to  last,  tlu!  bloom  passes  through  nine  or  ten  groov<>s,  and 
is  reduced  from  five  indues  diametc^r  and  fifteen  inclu's  long,  to 
a  flat  bar  three  inclii's  wide,  lliree-rpiarters  of  an  inch  thick,  and 
elc'ven  f(;et  long.  Tlio  rolling  and  returning  over  tho  rolls  oc- 
cupies a  minute  and  a  qtiarter  ;    the  Bhingling,  half  n  minute  ; 


Manufacture  of  wrought  iron.  t3 

and  from  t  ae  cliarging  of  the  refined  metal  to  the  delivery  of  the 
finished  puddle-bar  nearly  one  hovir  and  a  half  will  have  elai^sed. 

A  considerable  difference  is  observed  in  the  quality  of 
puddle-iron,  from  the  two  methods  of  refining.  The  blast-refin- 
ed iron  possesses  greater  fibre,  and  altogether  produces  a  better 
malleable  iron  than  the  product  of  the  reverberatory  furnace. 
Chemical  analysis  shows  the  latter  to  contain  an  excess  of  phos- 
phorus and  sulphur,  and  also  a  larger  quantity  of  silicon. 
Their  presence  in  greater  quantity  seems  to  point  to  the  incom- 
jjleteaess  of  the  reverberatory  process  for  refining.  The  irons 
made  by  this  process  are  very  generally  hot-short  (that  is,  brittle 
when  hot),  and  incapable  of  being  rolled  into  some  intricate 
forms  of  finished  bar-iron.  When  cold,  however,  the  purest 
specimens  possess  considerable  tenacity. 

It  is  a  question  whether  the  cleansing  the  iron  of  the  alloyed 
matters  can  be  efficiently  performed  in  a  single  operation,  with- 
out the  employment  of  a  blast.  Chemically,  the  constituents  of 
refined  iron  from  the  blast-refinery  accord  very  nearly  with  the 
composition  of  puddle-bar  from  the  reverberatory  refinery. 
Hence  the  bars  from  the  former  are  more  pure,  by  the  quantity 
of  alloy  removed  in  the  puddling  process.  This  defect  of  boiled 
bars  deserves  the  serious  consideration  of  manufacturers  in  more 
than  one  district,  which  recently  has  lost  its  character  for 
making  superior  qualities  of  merchant  iron. 

Tlie  matters  in  allot/  are  principally  derived  from  the 
ore  ;  the  sulphur  partly  froin  the  fuel.  In  the  preparation,  then, 
of  the  best  irons,  especial  attention  must  be  i:)aid  to  the  constitu- 
ents of  the  ore  used  in  the  smelting-furnace.  If  these  are  un- 
favorable as  to  qiiality,  it  is  hopeless  to  attemjjt  the  complete 
separation  of  the  injurious  ingredients  in  subsequent  processes, 
other  than  with  a  ruinous  waste  of  metal  and  labor.  The  blast- 
refinery  removes  a  portion,  the  puddling  process  a  second  por- 
tion, and  the  reheating  furnace  a  further  quantity  ;  but  the  re- 
sulting malleable  iron  is  still  contaminated  by  the  presence  of 
minute  quantities  of  the  alloy,  which  it  is  nearly  impossible  to 
wholly  eradicate.  Phosphorus  and  sulphur  are  commonly  con- 
sidered the  substances  which  exercise  the  greatest  deteriorating 
influence  on  quality;  it  is,  however,  highly  probable  that  silicon, 
calcium,  magnesium,  and  a  few  other  substances,  impair  the 
quality  to  nearly  an  equal  extent. 

The  cinders  produced  in  the  puddling  process  appear  to 
be  of  a  different  composition  to  those  from  the  boiling  furnace. 
The  latter  displaj'  a  larger  amount  of  lime,  phosphoric  acid,  sul- 
phur, and  silica  ;  in  fact,  are  not  widely  difterent  from  some 
varieties  of  the  blast-refinery  cinder.  By  adding  together  the 
constituents  of  the  refinery  and  puddling  cinders,  it  is  seen  that 
the  proportion  of  injurious  matter  removed,  relatively  to  the 
quantity  of  iron,  is  very  much  larger  than  in  the  boiling  process. 

A.  difference  of  quality  is  observed  between  the  iron  worked 
with  a  forge-hammer,  and  such  as  is  worked  with  a  squeezer. 
The  former  is  found  to  be  more  tenacious  and  freer  from  cinder 
than  the  latter.     This  difference,  it  is  generally  believed,  arises 


74  MANUFACTURE    OF   WROUGHT   IROIT. 

from  the  motion  of  the  squeezer,  which  is  grailual  and  iiressing, 
while  the  hammer  violently  expels  the  impurities  by  heavy  blows 
given  in  quick  succession.  A  preference  is  very  generally  given 
to  the  hammer,  where  the  quality  is  considered  of  paramount 
importance. 

The  lKiU'm<f-up  of  the  iron  in  the  puddling  process  is  a 
highly  interesting  point  in  the  manufacture,  insomuch  that  it 
forms"  the  connecting  link  between  cast  and  malleable  iron.  Up 
to  this  point  in  the  operation  the  iron  is  brittle,  devoid  of  malle- 
ability, and  melts  readily  at  a  temperature  between  2,000  and 
3, 00 J  Fahrenheit's  thermometer.  After  the  balling-up  and  the 
manipulation  of  the  shingle,  the  iron  is  malleable,  tenacious, 
and  fuses  only  at  a  very  high  temperature. 

Chctnical  (imtli/sis  hitherto  has  failed  to  inform  us  of  the 
cause  of  malleability 'in  iron,  since  no  appreciable  difference  can 
be  detected  between  bar-irons  and  some  crude  cast  irons.  The 
latter  may  be  deprived  of  its  alloy  so  as  to  produce  an  iron  simi- 
lar in  composition  to  bars,  yet  the  malleable  principle  is  want- 
ing. Crude  cast  irons  mado  from  the  rich  hematites  of  Lanca- 
shire and  Cumberland,  appear  to  be  l(>ss  brittle  than  others,  and 
possess  a  limited  amount  of  elasticity;  in  other  respects,  how- 
ever, they  show  the  characteristics  of  cast  iron.  Exposing  thin 
castings  from  these  ores  to  heat  along  with  ground  hematite  in 
clo.se  vessels  for  a  long  period,  results  in  the  abstraction  of  most 
of  the  carbon,  and  the  conscstiuent  production  of  limited  malle- 
ability. Attempts  have  been  maths,  and  are  now  being  made,  to 
convert  the  crude  cast  iron  into  wrought  iron,  by  a  system  of 
blast-refining  without  fuel,  and  subsequent  application  of  the 
hammer  or  S(iueezer — a  process  which  we  shall  describe  in  de- 
tail, althougli  it  has  not  as  yet  attained  such  certainty  as  to  justify 
a  decided  opinion  of  its  merits.  Mere  refining,  however,  even 
with  tlie  addition  of  tiuxes,  fails  to  produce  malleable  iron. 
Manipulation  to  a  certain  extent  is  essential  to  the  development 
of  the  malleable  principle,  which  then  progresses  jjroportionately 
with  the  working.  Various  oxides  and  snlphurets,  however, 
possess  the  property  of  retarding  and  sometimes  entirely  de- 
stroying the  agglutinous  character  of  the  iron  at  the  critical 
point.  Their  presence  is  shown  by  the  inability  of  the  puddler 
to  ball  up  his  iron,  which  persists  in  nitainin^^  the  consistency 
of  a  dry  pebbly  mass. 

Tlu'  trc.Ulhui  prhiriplj'  of  trroiUfht  *j'o*/,  also  devel- 
oped at  this  critical  point  in  the  operation,  is  etjually  character- 
istic of  the  singular  i)roperties  of  the  metal.  Here,  also,  analysis 
fails  to  point  out  the  acting  cause  why  some  irons  are  (lapabh;  of 
welding  and  othi^rs  not;  nor  does  it  explain  tlie  reason  of  iron 
Vjeing  so  pre-eminently  distinguished  for  tliis  inoperty  over  all 
other  metals.  Various  theories  have  been  propoundi<l,  but  the 
most  feasible  exi)lanation  of  the  welding  ap)>ears  to  be  the  acces- 
KJon  of  a  <iuanfity  of  heat,  su(iicieiit  for  softening  and  uniting 
the  two  i)ieces  by  ]iressure,  considenibly  before  the  teiiii)eratnro 
of  fusion  is  attained.  Metals  api>aniitly  devoid  of  this  iirinciplo 
retain  their  hardness  uj)  to  the  moment  of  li(|Uera(rtion;  conse- 
quently no  opp(jrtunity  is  offered  for  union  in  the  malleable  state. 


MANUFACTURE    OP   WROUGHT   IRON,  75 

Cutting  Puddle-Bars  to  Length. 

This  is  performed  by  powerful  lever  shears,  containing  steel 
knife-edges,  driven  by  the  same  power  as  the  rollers,  and  at 
nearly  similar  velocities.  The  propoi-tions  of  the  shears  intended 
for  cutting  bars  cold,  are  considerably  heavier  than  for  bars  di- 
rect from  the  finishing  rollers.  Knives,  four  inches  deep,  one 
and  a  half  inch  wide,  and  sixteen  inches  long,  bolted  to  the  fixed 
and  movable  arm  of  the  apparatus,  are  a  common  proportion. 
Great  care  is  required  that  the  knives  pass  each  other  with  a 
certain  degree  of  tightness,  or  the  wedge-like  action  of  the  flat  bar 
at  the  point  may  break  ofl"  the  movable  arm.  This  is  more  espe- 
cially the  case  with  shears  for  cutting  cold  iron,  which,  in  ad- 
dition to  being  kept  in  contact,  require  the  knives  at  all  times 
to  be  clean  with  a  sharp  V-cutting  angle.  The  knives  of  shears 
cutting  hot  bars  are  kept  from  softening  by  a  small  current  of 
water  directed  against  them;  but  the  same  degree  of  sharpness 
is  not  required  here  as  in  cold  shearing. 


Piling  the  Cut  Puddle-Bars. 

To  convert  the  puddle-bars  into  the  various  forms  of  the  fin- 
ished malleable  iron  met  with  in  commerce,  the  short  pieces  from 
the  cutting-shears  are  piled  one  on  the  other  to  form  a  mass  of  a 
weight  suited  to  the  weight  of  the  bar  to  be  operated  on.  Ihe 
piles  vary  greatly  in  size  and  arrangement,  according  to  the 
magnitude  and  purpose  of  the  finished  bar.  If  common  bar-iron 
of  average  size  be  the  order  of  the  day,  they  will  measure  some 
two  feet  long  and  four  inches  square;  with  larger  sizes  they  meas- 
ure five  or  SIX  feet  long  by  ten  or  twelve  inches  square.  A  nearly 
uniform  size  in  the  pieces  composing  the  pile,  whatever  be  its 
dimensions,  is  essential  to  successful  results.  The  piles  are  con- 
structed to  the  number  of  six  or  seven,  or  nioi'e,  on  an  iron  frame 
standing  about  two  feet  above  the  floor,  from  whence  they  are 
taken  as  required  by  the  workmen  engaged  in  bringing  them  to 
a  welding-heat  preparatory  to  rolling. 


Heating  Furnace. 

A  rcverberatory  furnace  of  nearly  the  same  dimensions  as  the 
puddling-furnace,  but  having  a  refractory  silicious  sand-bottom, 
is  employed  in  heating  the  piles.  The  bottom  is  rendered  even, 
and  declines  from  the  charging  door  to  the  back  and  flue,  for  the 
flow  of  the  liquid  cinder.  Cast  iron  framing,  with  tension  bolts 
to  restrain  the  pressure  of  the  arched  roof,  and  the  same  power- 
ful chimnej^  are  required  as  in  the  puddling-furnace.  The  piles 
are  inserted  into  the  furnace  on  a  "peeler,"  and  disposed  on  the 
bottom  in  such  manner  that  the  workman  can  readily  turn  them 
over,  or  grasp  them  for  withdrawal.  The  number  charged  at  one 
time  is  inversely  as  the  size;  but  for  small  piles  of  the  dimensions 
given  above,  they  may  be  taken  at  eight  or  ten.     When  properly 


76  MANUFACTURE   OF   WROUGHT   IRON. 

disposed  on  the  bottom,  the  charging-door  is  shut  and  all  en. 
trance  of  air  around  it  prevented  by  a  thick  dusting  of  small- 
coal  or  ashes.  The  grate  is  now  cleaned  of  adhering  matters, 
coals  added  to  the  fire,  the  stoke-hole  closed  with  the  fuel  so  as 
to  prevent  the  admission  of  air,  and  the  damper  opened  to  its 
widest.  An  intense  heat  is  generated,  and  communicated  by  de- 
flecting from  the  roof  to  the  charge  in  the  body  of  the  furnace. 
The  piles  receive  the  heat  unequally,  those  nearest  the  fire-place 
being  heated  first;  it  is  the  duty  of  "the  attendant  to  inspect  from 
time  to  time  the  condition  of  the  charge,  and  by  exposing  them 
alternately  to  the  strongest  action  of  the  fire,  to  heat  them  to  the 
same  temperature,  occasionally  turning  them  over  to  expose  the 
under  side  equally  with  the  others.  When  the  piles  are  large, 
turning  over  to  heat  the  under  side  is  the  only  operation  to 
which  they  are  subjected  in  the  furnace.  At  a  white  heat  the 
softening  of  the  iron  is  followed  by  the  flowing  of  a  quantity  of 
cinder  from  the  interstices,  which  nins  down  the  flue  to  the 
exterior  of  the  chimney.  Considerable  dexterity  is  required  in 
managing  the  fire;  for  though  in  theory  the  mere  heating  of  a 
few  masses  of  iron  may  seem  a  very  simple  operation,  in  practice 
it  is  difi&cult  of  attainment  economically.  The  flow  of  cinder 
over  the  mass,  when  at  a  white  heat,  protects  them  to  a  con- 
siderable extent  from  oxidation;  but  great  care  must  betaken 
that  no  air  gains  access  to  the  iron  during  the  process.  If  this 
precaution  be  neglected,  and  air  enters  the  furnace,  either  through 
the  fire  being  too  open  or  tlie  door  imperfectly  sealed,  the  metal 
is  rapidly  o.vidized,  and  great  loss  results.  The  particles  of  oxide 
of  iron  formed,  eventiially  cool  into  brittle  scales,  which  cut  into 
the  malleable  iron,  and  destroy  its  continuity  in  the  subsequent 
processes.  If  allowed  to  proceed,  the  oxidized  surfaces  of  metal 
cannot  be  brought  to  a  welding  condition;  and  whatever  pressure 
be  applied,  the  pieces  of  pudille-bar  composing  the  pile  cannot 
be  forced  into  union. 

It  may  be  here  nMuarked,  that  by  bringing  gaseous  and  solid 
carbon  in  contact  with  the  oxide  in  the  blast -Yurnace,  the  oxygen 
forms  new  combinations,  liberating  the  iron  in  the  metallic  state. 
The  superior  affinity  at  high  temperatures  of  carbon  over  iron 
for  oxygen,  has  been  taken  advantage  of  from  time  immeniorial 
for  the  ready  separation  of  oxygen  in  oxides  of  iron.  But  in  its 
progress  from  the  blast-furniice  to  the  state  of  a  finished  bar  of 
malleable  iron,  in  the  absence  of  carbon,  the  iron  has  a  constant 
tendency  to  return  to  the  condition  of  an  oxide.  In  the  blast- 
refinerv,  onedialf  of  the  metal  \\ould  be  oxidized,  were  it  not  for 
th(!  strutiim  of  carbon  fuel  covering  the  molten  iron,  and  which 
decoiii|)oses  the  oxide  nearly  as  fast  as  it  is  foruK'il.  In  the  pud- 
dling-'iirnace  the  metal  is  unprotected  by  carbon,  and  the  great- 
est care  and  skill  is  demnnded  from  tlie  puddler  tli.it  a  large  por- 
tion is  not  lost  through  wasteful  oxidation.  The  heating  process 
is  similarly  situated;  access  of  air  to  the  iron  causing  a  portion 
to  revert  to  its  original  state  in  the  ore.  So  much  of  the  iron  as 
is  thus  oxidized  in  the  several  processes  pass<!S  back  to  the  blast- 
firnace,  to  l)e  again  reduced  liy  jiresenting  to  the  oxido  the  Cftr- 
boa  necessary  for  liberating  the  luetul. 


MANUFACTURE    OF   WROUGHT   IRON.  77 

Tlie  heating  the  charge  to  the  requisite  temperature  is 
accomplished  in  forty-five  or  fifty  minutes,  when  the  bars  are 
withdrawn  singly  by  grasping  them  with  a  pair  of  heavy  tongs, 
and  conveying  them  on  a  light  carriage  to  the  rollers.  A  frequent 
practice  is*  to  drag  the  white-hot  pile  on  the  metal  floor  of  the 
mill  to  the  rollers;  but  such,  a  proceeding  scarcely  ever  fails  to 
soil  the  iron,  and  injure  the  quality  to  a  slight  extent.  Where 
the  quality  is  sought  to  be  superior,  too  much  care  cannot  be 
taken  to  keep  the  iron  from  contact  with  deleterious  substances. 

The  cinder  flowing  from  the  iron  is  contaminated  by  the  addi- 
tion of  a  portion  of  the  fused  sand  of  the  furnace-bottom,  as  also 
by  the  small  quantity  of  brick-work  of  the  interior  fused  by  the 
intensely  high  temperature.  The  composition  of  the  cinder  varies 
with  the  iron  and  treatment;  generally  it  contains  sixty  or  sixtj'- 
five  per  cent,  of  protoxide  of  iron,  twenty-nine  or  thirty  of  silica, 
with  smaller  quantities  of  protoxide  of  manganese,  alumina, 
phosphoric  acid,  lime,  magnesia,  and  sulphur. 


The  RoUing-Mill. 

TJie  rollers  used  in  this  process  \a,Ty  in  size  with  the  iron  to 
be  reduced:  heavy  bars  are  rolled  between  rollers  of  eighteen  or 
twenty  inches  diameter;  lighter  bars  between  rollers  twelve  and 
fourteen  inches;  and  the  smallest  sizes  in  mills  have  rollers  six 
to  eight  inches  diameter.  A  heavy  rolling-mill  consists  of  two 
pairs,  distinguished  as  "roughing"  and  "finishing"  rollers,  with 
shears,  saws,  and  other  appendages  for  completing  the  operations 
on  the  bar,  in  addition  to  the  eight  or  nine  heating-furnaces. 
The  roughing-roUers  are  commonly  about  six  feet  long,  the  fin- 
ishing about  half  as  much;  the  two  pairs  are  coupled  as  in  the 
puddling  train,  and  driven  at  speeds  varying  from  sixty  to  a  hun- 
dred and  twenty  revolutions  per  minute.  The  frames,  sole- 
plates,  connecting-spindles,  and  pinions,  are  required  to  be 
heavier  than  in  the  puddUng  process,  and  greater  accuracy  and 
finish  are  required  throughout.  When  a  steam-engine  is  em- 
ployed to  drive  the  trains,  the  size  ought  to  afford  100  horse- 
power to  each;  but  smaller  rollers  are  driven  with  proportionately 
less  power.  The  tooth-wheels  to  bring  up  the  speed  of  the 
rollers,  the  fly-wheel  to  equalize  the  speed,  and  the  shafts,  frame- 
work of  the  mill,  and  substructure,  require  to  be  proportionately 
heavy  and  strong.  All  the  parts  subject  to  strain  are  made 
many  times  stronger  than  a  casual  spectator  would  consider  ne- 
cessarj';  this  is  done  to  avoid  the  loss  of  iron  and  labor,  and  the 
ruinous  delay  necessarily  attendant  on  every  breakage  of  the 
inachinery  employed. 


Turning  the  Rollers. 

The  rollers  employed  are  made  of  cast  iron,  of  as  hard  tex- 
ture as  can  well  be  worked;  soft  iron  is  inadmissible.  They  are 
allowed  to  cool  in  the  mould,  having  been  cast  on  end  with  a 


78  Manufacture  of  wrought  iron. 

high  pressure  of  metal  to  insure  solidity  in  every  part,  without 
which  they  are  useless;  they  are  afterward  taken  to  the  lathes, 
and  placed  in  a  centring-lathe  for  turning  the  axles.     This  is 
done  by  the  projecting  end  of  a  wide  chisel,  firmly  held  horizon- 
tally by  wedging  in  a  cast  iron  frame,  and  pressed  against  the 
metal  of  the  roller  by  other  wedges  in  the  rear.     Motion  is  com- 
municated to  the  roller  through  the  intervention  of  powerful 
spur-gearing,   from    a   steam-engine   or   water-wheel.      Though 
rude,  this  process  is  more  expeditious  than  with  the  highly-fin- 
ished lathe  of  the  engine-manufacturer,  which  would  speedily  be 
rendered  imserviceable  if  forced  to  cut  oft",  at  each  revolution,  a 
thick  ring  of  cast  iron  from  a  cylinder  weighing  several  tons. 
From  the  centring-lathe  the  roller  is  taken  to  a  second  lathe  and 
placed  in  brasses  on  its  recently  turned  axles  ;   motion  is  hero 
communicated   to  it  through  the  intervention  of  strong  tooth- 
wheels  and  spindles  to  tlni  amount  of  two  or  three  revolutions 
per  minute,  depending  on  the  hardness  of  the  iron  and  the  size 
of  the  roller.      With  hard  iron  the  velocity  is  rediu-ed,  to  pre- 
vent softening  of  the  steel  cutting-tools  by  heating.    The  hardest 
rollers  cannot   be  advantageously  turned  at  greater  velocities 
than   one  revolution   in   three    minutes,    but   the   majority  of 
grooved  rollers  bear  turning  at  the  higher  velocity. 

The  Idthc  in  which  the  working  part  of  the  roller  is  turned, 
requires  to  be  exceedingly  strong;  a  minimum  section  of  100 
square  inches  of  iron  in  tlie  weakest  place  is  not  too  miich. 

The  first  operation  performed  on  the  body  of  the  roller  is  to 
reduce  it  to  a  smooth  cylinder  of  the  same  diameter  through- 
out. This  is  done  with  chisels  three  or  four  inches  wide,  resting 
on  iron  blocks  and  secured  in  the  desired  position  by  wedping 
as  in  turning  the  axle.  The  best  cast-steel,  carefully  tempered, 
is  demanded  for  the  CTitting-tools.  When  reduced  to  a  perfect 
cylinder,  the  motion  is  discontinued  and  the  design  inscribed 
on  its  periphery;  the  design  varies  with  the  section  of  the  bar 
which  it  is  intended  to  roll.  If  intended  for  a  cylindrical  bar, 
grooves  nearly  of  a  semi-circular  shape  are  cut  out  by  similarly 
shaped  tools,  during  the  revolution  of  the  roller;  sqiiare  bars 
have  the  grooves  of  a  triangular  shape.  On  placing  two  of  these 
together,  it  is  obvious  that  they  form  either  a  square  or  circular 
orifice  ;  and  if  made  to  revolve  so  that  the  peripheries  of  the 
rollers  when  in  contact  move  in  the  same  direction  and  with  the 
same  velocity,  a  soft  substance  interjjosed  is  forci'd  to  the  figure 

f»roduced  by  their  junction.  On  the  other  hand,  the  substitu- 
ion  of  a  plain  cylindrical  roller  on  one  part  would  result  in  the 
production  of  a  bar  having  a  section  cf)rn'si)ontling  to  the  semi- 
circular or  triangular  iorm  of  tlie  single  groove  used.  Flat  bars 
are  ])r()dui;c(l  on  Kimiiar  piiiicii)li-s  :  a  groove  of  the  retpiired 
widtli  is  sunk  in  the  roller  much  (li('])cr  tiiaii  tlic  intcndrd  thick- 
ness of  tlie  bar;  the  excess  bt'ing  filled  uj)  by  a  jirojt'cting  tongue 
on  the  top  roller.  By  mc^rely  altering  the  distances  of  the  two 
roliors,  bars  of  various  thicknesses  may  be  rolled  by  the  same 
jmir  of  rollers.  When  the  depth  of  the  groove  is  considerable, 
allowance  has  to  be  made  for  delivering  the  bar  freely,  by  widen- 


MANUFACTURE  OF  WROUGHT  IRON.       79 

ing  the  top  of  the  groove  so  as  to  give  it  a  slightly  tapering  form. 
This  tapering,  however,  interferes  with  the  parallelism  of  the 
sides  of  the  bar,  which  has  to  be  reversed  and  rolled  in  the  fin- 
ishing groove  twice,  by  which  the  deviation  from  the  parallel  is 
reduced  one-half ;  except  in  very  thick  bars,  the  remainder  is 
not  readily  perceptible  to  an  inexperienced  eye.  A  distorted 
figure  of  the  section  of  a  thick  bar  shows  the  effect  on  the  sides 
more  clearly.  By  careful  attention  to  the  form  of  the  groove  and 
projecting  tongue,  very  many  api^arently  difficult  sections  may 
be  rolled. 

The  reduction  of  the  white-hot  pile  of  puddle-bars  to  the 
finished  merchant-bars,  is  accomplished  by  a  STiccession  of 
rollings,  probably  twelve  or  fifteen  in  number,  each  time  through 
a  groove  smaller  in  section  than  the  preceding  one.  This  pro- 
duces successive  elongations,  corresponding  to  the  reduction  of 
metal  in  section.  It  is,  however,  necessary  to  observe,  that  the 
groove  through  which  the  bar  passes,  while  of  a  reduced  section 
and  smaller  in  one  direction  than  the  previous  groove,  in  the 
other  direction  it  is  required  to  be  longer.  The  rollers  in  their 
revolution  are  capable  of  pressing  the  iron  in  one  direction  only, 
viz.,  vertically:  the  degree  of  pressure  exerted  in  this  direction 
may  be  varied  at  pleasure,  by  allowing  the  rollers  to  recede  from 
each  other  to  diminish  it,  or  the  reverse  by  screwing  them  into 
closer  contact  with  the  ponderous  set-screws  in  the  frames.  But 
the  rollers  are  incapable  of  exerting  any  action  horizontally  on 
the  iron  in  the  direction  of  their  length.  If  the  bar  is  of  a  sec- 
tion that  admits  of  turning  on  edge,  and  passing  between  the 
rollers  in  this  way  alternately,  the  width  of  each  groove  is  gradu- 
ally diminished,  but  it  is  in  excess  of  the  height  of  the  preceding 
one.  Flat  bars  are  rolled  in  grooves  increasing  in  width  to  the 
last  or  finishing  ;  but  the  thickness  in  each  is  diminished  very 
rapidly.  With  very  thick  masses  of  iron  of  a  fla^^^-bottom  section, 
it  is  not  unusvial  to  work  half  in  each  roll,  and  afterward  remove 
the  angular  piece  at  the  side  by  repassing  it  through  the  last 
groove. 

To  insure  the  deliveri/  of  the  iron  freely  in  a  straight 
line  without  contortions,  great  attention  has  to  be  paid  to  the 
diameter  of  the  rollers  at  the  points  where  they  press  on  tihe 
iron.  If  one  be  larger  than  the  other,  the  periphery  of  the 
larger  roller,  b^'  moving  at  a  greater  velocity,  deiiects  the  iron 
from  it.  A  groove  or  tongue  of  one  roller  of  greater  diameter  on 
one  side  than  the  other,  unless  counteracted  by  a  corresponding 
enlargement  in  the  other  roller,  throws  the  iron  out  in  a  spiral 
direction,  from  which  it  is  almost  impossible  to  straighten  it. 
This  defect  in  the  turning  seldom  occurs  with  bars  of  common 
section,  but  unusual  sections  entail  a  mass  of  unseen  labor  in 
guarding  against  its  occurrence. 

The  interior  of  the  grooves  an^Vae  working  part  of  the 
tongue,  if  any,  it  is  preferable  to  keep  smooth.  This  is  absolute- 
ly essential  in  the  case  of  the  last  grooves  through  which  the  bar 
passes.  In  the  grooves  of  the  roiaghing-roUers,  it  is  common  to 
cut  notches,  or  otherwise  dent  the  working  surface,  to  insure  a 


80  MANUFACTURE    OF   ■WROUGHT   IRON. 

sufficient  adhesion  to  force  the  bar  through.  This  is  met  more 
effectively  by  increasing  the  diameter  of  the  roUers  to  the  largest 
practicable  point.  The  use  of  notches,  in  any  shape,  injures 
the  fibre  of  the  iron,  besides  affecting  the  surface  appearance  of 
the  bar. 

Alloivance  has  also  to  be  made  for  the  reduction  of  size 
which  the  bar  undergoes  in  cooling  from  a  rod  heat  down  to  that 
of  the  atmosphere.  The  measure  allowed  for  contraction  is 
affected  by  the  character  of  the  iron,  and  temperature  at  time  of 
delivery  from  the  groove  ;  but  one-fifth  of  an  inch  may  be  con- 
sidered a  fair  allowance  for  bars  one  foot  wide. 


Rolling  Bar-Iron. 

T7*e  white-hot  pile  from  the  heating  furnace  is  passed 
through  a  large  groove  in  the  roughing-rollers,  by  pushing  it 
forward  on  the  fore-plate  until  caught  and  drawn  through  by  the 
rollers.  If  the  pile  is  wtU  proportioned  to  the  groove,  it  passes 
through  easily  ;  but  if  too  large,  it  may  require  blows  from  the 
iron  carriage  to  make  it  enter  the  groove  :  should  this  occur,  and 
the  roughmg-rollers  be  a  small  distance  apart  at  the  largest 
diameter,  the  immenstt  vertical  pressure  on  the  iron  in  the  small 
groove,  forces  out  a  portion  each  side  in  the  form  of  a  thin  iJange. 
This  has  to  be  carefully  guarded  against,  as  from  its  thinness 
this  strip  of  iron  cools  rapidly,  and  may  become  too  cold  for 
turning  down  and  weldingin  the  succeeding  groove.  The  pile 
is  now  seized  by  a  second  worliuian,  with  a  heavy  pair  of  tongs  ; 
and  two  hooked  levers,  suspended  by  chains  from  the  roof  of  the 
mill,  are  inserted  underneath,  lifting  it  up  over  the  top  roller 
and  delivering  it  on  the  other  side.  In  its  descent  the  first 
workman  turns  it  over  at  a  right  angle  from  its  former  direction, 
and  pushes  it  toward  the  next  smaller  groove  until  it  is  drawn  in. 
The  lifting  back  and  rolling  o))erations  in  the  rougliing-rollers  are 
repeated  till  a  suitable  reduction  has  been  made  for  the  finishing 
rollers,  to  which  it  is  eventually  transferred,  resting  on  the 
hooked  levers.  In  these  it  is  roUe'd  five  or  six  times,  through  as 
many  diminishing  grooves,  to  the  recpiired  section,  each  time 
turned  partly  around,  or  the  position  in  regard  to  the  jointing  of 
the  rollers  otherwise  altered.  With  a  heavy  strain  and  soft  iron, 
constant  attention  is  i)aid  to  the  action  of  the  rollers,  that  no 
side  fliinge  !)(■  formed  on  the  bar. 

The  foi>  roller  is  made  a  fraction  larger  than  the  bottom, 
in  onler  to  throw  the  liar  down  on  the  guides  as  it  is  delivered 
>)y  the  rollers.  Tlie  guides  are  two  tiers  of  heavy  wedges,  the 
points  f)f  the  top  tier  resting  on  tlie  toj)  of  the  bottom  roller, 
while  th(!  lower  tier  is  k<'|)t  in  reserve  iimiKMliutely  below.  In 
its  delivery  the  liar  is  coiidueted  in  a  straight  line  by  these 
wedg<'s,  instead  of  turning  down  underneatli  the  roller,  as  it 
otherwise!  woidd.  If,  fnun  accident,  the  guides  opjwsite  any 
(me  groove  are  displaced,  the  end  of  the  bar  is  likely  to  return 
under  the  roll,  and  lio  united  witli  the  other  ]>art  into  a  solid 
ring.     This  untoward  accident  may  also  occur  through  defect  in 


MANUFACTURE   OF   WROUGHT   IRON.  81 

the  iron,  the  more  so  if  partially  oxidized  by  long  exposure  in 
the  heating  furnace.  In  this  case  a  portion  of  the  pile  separates 
from  the  rest,  and  following  the  course  of  the  top  roll,  is  welded 
into  a  massive  iron  ring  Considerable  delay  occurs  under  such 
circumstances,  for  operations  must  be  suspended  while  the  iron 
ring  is  being  cut  through  ;  and  this  requires  some  time  when 
the  metal  is  hveor  six  inches  wide  and  half  as  much  in  thickness. 

With  some  sections  great  exactness  is  required,  and  a  de- 
viation of  the  thickness  of  a  hair  either  way  renders  the  bar 
iinsalable.  If  obliged  to  work  to  a  very  exact  section,  the  rollers 
are  adjusted  with  the  greatest  care,  the  tightening  and  set- 
screws  without  play,  and  frequent  examinations  made  of  the  bars 
produced.  With  the  greatest  care,  however,  a  few  daj^s  at  most 
results  in  so  much  abrasion  in  the  rollers,  that  they  have  to  be 
sent  to  the  turner  for  repairs.  'Where  they  rub  on  each  other, 
the  surfaces  are  frequently  lubricated  with  black-lead  and  grease, 
or  carbonaceous  matter  and  palm  oil. 

The  ovevheatinf/  of  the  roUevs,  by  contact  with  the  hot 
iron,  is  pi-evented  by  small  streams  of  water  directed  on  the 
parts  of  the  finishing-rollers  liable  to  heating.  "With  bars  of  a 
concave  section  on  the  upper  surface  in  rolling,  the  water  which 
falls  on  the  red-hot  charcoal  affords  an  instructive  example  of 
the  spheroidal  condition  of  water  in  contact  with  substances  at 
high  temperatures.  "While  the  bar  remains  at  a  bright  red-heat, 
no  steam  is  formed,  the  drops  of  water  merely  rolling  over  the 
surface  ;  but  the  surface  of  the  rollers,  though  scarcely  heated 
above  the  boiling  point  of  water,  is  enveloped  in  clouds  of  steam. 
These  phenomena  of  water  were  known  to  operatives  in  rail- 
rolling  mills  many  years  before  the  publication  of  M.  Boutigny's 
experiments. 

Daring  the  successive  rollings,  the  great  pressure  ex- 
erted on  the  bar  expels  with  violence  a  portion  of  the  remaining 
cinder,  and  leaves  the  iron  comparatively  i^ure.  This  cinder  is 
composed,  to  the  extent  of  about  ninety  per  cent.,  of  magnetic 
oxide  of  iron;  the  remaining  ten  percent,  of  silica,  phosphoric 
acid,  lime,  sulphur,  and  other  bases,  depending  on  the  local 
constitution  of  the  crude  iron. 


Cutting  Bar-Iron  to  Length. 

The  finished  hnv  is  taken  from  the  rollers  and  cut  to  the 

required  length  whilst  hot.  This  is  done  either  by  lever 
shears,  as  in  the  case  of  puddle-bars,  or  circular  saws  revolving 
at  great  rapidity.  The  latter,  a  modern  invention,  performs  the 
work  in  an  exceedingly  neat  and  expeditioiis  manner,  and  is 
applicable  to  iron  bars  of  all  sizes  irrespective  of  section— an  ad- 
vantage not  possessed  by  any  shears.  Thin  merchant-bars  are 
frequently  cut  cold,  in  order  to  show  off  the  texture  of  the  iron; 
but  large  bars  of  every  description  are  cut  whilst  hot.  The 
sawing  apparatus  consists  of  a  pair  of  steel  disks,  four  feet  diam- 
eter and  one-eighth  of  an  inch  thick,  with  coarse  teeth  on  the 

4* 


82  MANUFACTURE   OP    WllOUGHT   IRON. 

edges,  mounted  on  a  spindle  about  four  feet  long.  By  a  small 
pulley-wheel  on  the  centre  of  this  spindle,  motion  is  communi- 
cated by  bands  from  larger  wheels  driven  by  the  engine.  Against 
the  outside  of  each  saw,  but  near  its  front  edge,  is  placed  a  nar- 
row sliding-frame  of  cast  iron,  equal  in  length  to  the  longest  bar 
rolled,  on  wliich  the  red-hot  bar  is  placed  and  retained  in  its 
position  by  stops.  The  ragged  end  of  the  bar  is  made  to  project 
sufficiently  in  front  of,  and  finally  pressed  against,  the  saw,  by 
which  it  is  cut  from  the  body  in  a  few  seconds.  If  gradually 
performed  in  fifteen  or  sixteen  seconds,  with  good  saws,  the  emls 
of  the  bar  have  a  smooth,  polished  apjiearance  ;  performed  in 
three  or  four  seconds,  the  ends  are  less  smooth.  The  second 
end  of  the  bar  is  cut  in  a  similar  manner  by  the  other  saw;  the 
projecting  ends  ciit  off"  being  placed  aside  for  remanufacture. 
Great  care  is  commonly  reqiiired  in  cutting  the  second  end,  as 
the  amount  then  cut  off  regulates  the  length  of  the  bar.  To  in- 
sure the  recjuisite  accuracy  in  this  respect,  the  second  movable 
])latform  is  furnislied  with  a  sliding-gauge,  the  distance  of  which 
from  the  face  of  the  saw  regulates  the  length  of  the  finished  bar. 
Allowance,  however,  has  to  bo  made  for  contraction  of  the  bar 
from  its  red-hot  state;  and  some  attention  requires  to  be  given 
to  the  (litference  of  temperature  at  which  some  are  cut,  in  order 
to  obtain  bars  of  ncarl  /  uniform  length. 

Ttw  sinrs  vci'itlre  1,000  to  1,5()0  revolutions  per  minute, 
equal  to  a  velocity  at  the  cutting-edge  of  1-12  to  213  miles  per 
hour.  Their  edges  are  kept  from  overheating  by  dipping  into 
narrow  cast-iron  cisterns  containing  water.  When  cutting,  the 
shower  of  sparks  created  is  \.artialiy  confined  to  the  vicinity  of 
the  saws  by  sheet-iron  casings,  supported  over  the  upper  edges 
of  the  saw.  The  entire  apparatus  requires  to  be  fitted  up  very 
correctly,  the  revolving  parts  evenly  balanced,  and  working  in 
good  brasses  rigidly  fixed  to  jiedcstals  and  a  heavy  substructure. 
Every  twenty- [our  hours  the  saws  require  sharpening,  and  are 
then  replaoe<l  l-y  othci-s. 

The  CHtthiij  into  Ir n f/f Ii s  com\Ai'to(\,  the  bar  is  straight- 
ened by  woodtin  mallets  on  a  massive  cast-iron  jilane  placed  level 
witli  the  floor;  the  asperities  of  the  edge,  from  the  action  of  the 
saw,  removed  witli  a  coarse  file,  and  tlie  trade-mark  of  the  maker 
stamped  upon  it,  when  the  operations  attending  the  manufac-turo 
of  a  mereliant-biir  terminate.  The  iron  so  ])roduced  is  known 
amongst  manufacturers  as  No.  2,  from  liaving  been  twice  rolled. 
In  commerce  it  is  known  as  common  bar-iron. 


RccapitiQation  of  the  Process. 

In  tracing  the  jirogress  of  the  metal  from  the  state  of  an  oxide 
in  tli*^  ore  tliroiigli  tlie  several  transformations,  finally  ending  in 
the  j)ro(lucti(m  of  a  bar  of  malleable  iron,  it  is  seen  that  recourse 
is  had  to  heating  in  (-lose  or  open  furnaces  five  times,  viz.,  cal- 
cining, smelting,  refining,  i)uildling  and  heating.  Hut  fre- 
quently the  bar  is  pnxhK^'d  witli  four  heatings;  an<l  by  a  modifi- 
cation of  the  refining  proces.s,  at  one  time  largely  adopted  ia 


MANUFACTURE   OP  WROUGHT  IRON.  83 

Staffordshire,  and  to  a  less  extent  in  South  Wales,  only  three 
heatings  were  required  from  the  ore  to  the  finished  bar.  In  the 
first  process— the  calcining  of  the  ore— it  is  heated  to  a  high  tem- 
perature, and  allowed  to  cool  down  for  filling  into  the  blast- 
furnace: the  author  is  of  opinion  that  this  is  a  process  properly 
beloncfing  to  the  blast-furnace,  where  the  calcination  could  be 
effected  without  loss  of  heat  as  at  present.  In  the  smelting  pro- 
cess, the  ore  is  again  heated,  f  .ised  along  with  fluxes,  and  descends 
to  the  lower  hearth  as  crude  iron,  whence,  in  many  works,  it 
flows,  -wathout  cooling,  into  the  refinerj'  furnace.  The  product 
of  this  furnace  may  either  be  malleable  blooms,  or  refined  metal, 
according  to  the  kind  of  furnace  used. 

A-SSiiniing  that  the  crude  iron  is  refined  by  the  boiling  i^ro- 
cess,  the  heat  imparted  the  metal  in  the  blast-furnace  will  last 
through  the  whole  process  of  refining,  balling-up,  conveyance  to 
hammer  or  squeezers,  shingling,  removal  to  the  rollers,  rolling 
in  two  pairs  of  rollers,  removal  to  the  shears,  cutting  into  short 
lengths.  It  is  now  allowed  to  cool,  is  piled,  and  the  mass 
heated  in  the  heating  furnace,  from  whence  it  is  taken  to  the 
roughing-rollers,  where  it  is  roughed  to  a  thick  massive  bar;  re- 
moved to  the  finishing-rollers,  and  rolled  to  a  square,  round,  or 
flat  bar,  as  may  be  required.  It  is  now  drawn  out,  the  ends  cut 
with  a  circular  saw,  straightened,  filed  clean  at  the  ends,  and, 
finally,  stamped  with  a  trade-mark  and  placed  aside  as  a  finished 
bar.  with  one  single  heating. 

Tl^e  several  meehanicaJ  operations  performed  in  the 
forge  and  mill  on  masses  of  iron  weighing  several  cwts.  are  exe- 
cuted with  admirable  precision  and  dexterity.  Frequently,  the 
same  bar  is  passed  fifteen  or  sixteen  times  between  the  rollers, 
and  has  to  be  grasped  and  released  twice  this  number  of  times 
with  a  pair  of  heavy  tongs,  when  moving  at  the  rate  of  nearly  six 
miles  per  hour.  In  its  progiess,  also,  in  the  rollers  it  has  to  be 
adjusted  in  a  different  direction  each  time  it  is  passed  between 
them.  When  it  is  considered  that  the  substance  thus  handled  is 
a  white-hot  piece  of  iron,  exposing  a  surface  of  from  twelve  to 
thirty-five  feet  to  the  operatives,  and  in  a  temperature  compared 
with  which  the  torrid  zone  is  cold,  the  great  skill  of  the  men, 
and  the  severe  bodily  labor,  will  be  seen  to  surpass  everything 
having  the  least  analogy  in  the  industrial  arts  of  any  country. 

From  the  period  when  the  bloom  leaves  the  puddling-furnace 
to  the  delivery  of  the  puddle-bars  from  the  shearing  apparatus, 
five  or  six  minutes  will  have  elapsed;  the  time  occupied  in  con- 
veying the  pile  from  the  heating  furnace,  and  siibmitting  it  to 
the  several  finishing  operations,  seven  to  eight  minutes. 

It  may  be  remarked,  that  in  both  pairs  of  rollers  in  puddling, 
and  also  in  the  rolling-mill,  the  violent  compression  of  the  iron 
is  attended  with  the  evolution  of  large  quantities  of  caloric;  so 
much  so,  indeed,  that  it  compensates,  to  a  great  degree,  for  the 
loss  by  radiation  and  from  the  currents  of  water  thrown  on  the 
finishing-rollers.  The  quantity  of  caloric  thus  evolved,  appears 
to  vary  with  the  character  of  the  iron.  The  South  Wales  irons 
require  to  be  rolled  quickly,  or  the  bar  becomes  too  cold  and 


84  MANUFACTURE    OP   WROUGHT   IRON. 

hard  for  compression.  South  Stafifordsliire  iron,  on  tlie  othet 
hand,  may  be  rolled  slowly,  and  is  compressible  between  rollers 
at  greatly  lower  temperatures. 

TJie  exjteiKlitiire  of  j)oit'er  in  forcing  the  iron  into  shape 
in  the  larger  mills  is  very  great.  Fly-wheels,  eighteen  feet  in 
diameter,  having  fifteen  tons  of  metal  in  the  rim  alone  and  pro- 
pelled by  powerful  engines  at  the  rate  of  120  revolutions  per 
minute,  are  brought  down  to  half  this  speed  in  four  or  five  sec- 
onds, simply  from  the  resistance  of  the  iron  to  compression,  when 
from  any  cause  the  temperature  is  slightly  reduced.  The  ex- 
penditure of  force  in  reducing  a  pile  to  a  flat  bar  six  inches  by 
one  inch,  and  fifteen  feet  long,  is  equal  to  the  lifting  of  4,500 
tons  one  foot  high. 


Manufacture  of  Railway  Bars. 

Rolling  r<(ihr<nj  iron  is  conducted  in  a  nearly  similar 
manner  to  that  pursued  with  other  large  bars.  The  piles  are 
larger;  and  if  a  superior  quality  is  desired,  great  care  is  taken  in 
the  arrangement  of  the  several  pieces  of  puddle-bar.  In  the  fin- 
ishing-rollers, the  reduction  of  the  iiltimate  section  is  performed 
by  a  succession  of  intricately-shaped  gruoves.  The  turner's  skill 
is  severely  taxed  to  adapt  the  grooves  in  these  rollers  to  each 
other,  and  at  the  same  time  to  deliver  a  clean  bar  of  the  precise 
section.  This  frequently  requires  a  careful  selection  of  the  ores 
used  in  the  production  of  the  crude  iron  of  part  or  the  whole  of 
the  puddle-iron  in  the  i)ile,  according  to  the  strain  exerted  on 
different  parts  of  it  in  rolling  to  a  bar.  The  bar  first  enters  the 
groove  on  the  left-hand  side,  and  is  successively  passed  on  to  the 
right-hand  groove,  from  whence  it  emerges  exhibiting  the  re- 
quired section.  This  form  of  bar  is  one  of  the  most  difficult  to 
roll;  a  considerable  portion  of  it  is  thin,  consequently  liable  to 
coiil  quickly.  A  still  greater  difficulty  is  met  with  in  the  differ- 
ence in  diameter  of  the  working  portions  of  tlie  grooves;  the 
smallest  diameter  occurs  at  the  edges  of  the  thin  flanges.  In 
consequence  of  this  difference  of  diameter,  the  several  portions 
of  the  V)ar  are  not  projv^lled  with  the  same  velocity;  the  greatest 
movement  occurring  witli  the  largest  diameter,  and  vice  vtrsa. 
"With  wide  fliing('  rails  the  dift'crenco  is  very  considirable;  for 
instance,  tlie  purt  of  tlie  roller  bearing  on  the  body  "f  tht?  bar 
will  move  at  the  rate  of  six  miles,  while  the  bottom  of  tlie  groove, 
which  jiresses  on  the  flanges,  will  move  only  five  miles  per  hour. 
The  distention  of  the  jiarts  of  the  bar  is  in  direct  ratio  to  the  di- 
ameter (tf  the  roller  of  that  ])art;  hence,  a  direct  tendency  to  drag 
the  thi(;k  portion  of  the  bar  away  from  tlie  flange.  To  counteraet 
it,  tlie  thin  ]iart  is  spread  out  to  a  great  width  in  the  second 
groove;  in  the  siunieeding  grooves  the  ad<litioiiiil  work  tlirown 
on  this  amply  coiii|ieiisates  for  the  lesser  distention.  Without  a 
provision  of  this  kind,  tlie  thin  edges  would  crack  ;  and  not  un- 
fre(|uently  long  strips  peel  off,  espcciuUy  with  iron  of  the  red- 
iihurt  chuss. 


MANUFACTURE   oP  WROUGHT   IRON*  85 

Riiil  bars  are  cut  into  lengths  with  circu'ar  saws.  In  con- 
sequence of  the  hoUowness  at  the  sides  or  bottom  they  cannot 
be  shorn  hot  with  any  degree  of  neatness  ;  and  the  adaptation  of 
cold  shears  to  the  purpose  frequently  leaves  a  hollow  cavity  in 
the  end,  and  is  altogether  a  tedious  operation.  The  first  bars 
manufactured  were  secured  in  heavy  cast-iron  blocks,  fitted  with 
counterparts,  and  closely  fitting  the  rail  all  round.  The  end  of 
the  bar  was  made  red-hot  before  insertion  in  the  cavity  of  the 
block,  and  then  cut  with  common  blacksmiths'  chisels,  any  in- 
equalities being  removed  by  filing.  The  substitution  of  revolv- 
ing saws,  however,  has  enabled  the  manufacturer  to  square  and 
finish  the  ends  at  less  than  one  twelfth  the  expense  incurred  with 
hand-blocks. 

After  the  ends  are  cleaned  by  filing  with  heavy  double-handled 
rasps,  the  railway  bar  is  subjected  to  the  hot  straightening  pro- 
cess. This  is  performed  on  a  massive  iron  block,  placed  over  its 
surface  the  length  of  the  rail,  and  cast  of  such  thickness  as  will 
prevent  flexure  by  heat.  Any  deviations  from  a  right  line  are 
taken  out  of  the  hot  bar  by  long-handled  wooden  mallets,  having 
heads  nine  or  ten  inches  diameter,  and  eighteen  or  twenty  long: 
iron  hammers  would  leave  an  impression  on  the  soft  iron,  and 
are  therefore  inadmissible  in  all  hot-straightening  operations.  If 
the  section  permit,  it  is  now  stocked  on  a  level  grated  floor, 
formed  of  bars  on  edge,  till  quite  cold. 

With  the  majovitif  of  bays,  however,  it  is  subjected  to  a 
further  hot-straightening,  or,  more  correctly,  hot-bending,  to 
counteract  the  unequal  contraction  of  the  several  parts  of  the  bar 
during  cooling.  In  the  two  sections,  the  lai'ger  portion  of  the 
metal  is  thrown  in  the  head  or  wearing  jiart  of  the  railway  bar. 
If  a  bar  of  either  of  those  sections  be  made  perfectly  straight 
when  at  a  bright  red  heat,  and  allowed  to  cool,  the  thinner  por- 
tions part  with  their  heat  and  contract  more  rapidly.  The  head 
containing  the  great  mass  of  metal  cools  very  slowly,  and  several 
hours  after  the  flanges  have  contracted  nearly  to  the  amount  due 
to  the  reduction  of  temperature,  this  part  continues  to  cool  and 
contract. 

In  practice,  this  inequality  of  construction  is  obviated  by 
curving  the  bar,  in  a  reverse  direction,  to  the  amount  of  curva- 
ture which  it  would  have  taken  if  allowed  to  cool  from  a  straight 
bar.  The  curve  taken  by  a  bar  in  cooling  forms  the  profile  of  a 
massive  cast-iron  block,  over  which  the  bars  are  successively  bent 
with  heavy  wooden  mallets.  In  doing  this,  attention  is  paid  to 
the  temperature  so  that  no  serious  deviation  occurs  from  that  at 
which  the  trial  rail-bar  took  its  curve.  Great  care,  indeed,  ought 
to  be  taken  to  insure  the  bar  taking  a  straight  line  with  its  loss 
of  heat,  or  permanent  injury  is  cai;sed  to  the  iron. 

If  the  hot  straif/hteniiuj  and  bending  have  been  well- 
conducted,  the  cold  bar  will  not  deviate  greatly  from  the  right 
line;  but  as  absolute  correctness  is  demanded  by  the  purchaser, 
the  huvs  subsequently  undergo  a  series  of  cold  straightenings  by 
hammers  or  pressure.  Formerly  the  heavy  sledge-hammer  ('J4 
lbs.  weight)  was  the  only  instrument  used;  but  of  late  years  the 


86  MANUFACTURE    OP  WROUGHT   IRON. 

increased  weight  and  stiffness  of  the  bars,  and  the  general  desire 
to  reduce  the  cost  of  manufacturing,  have  resulted  in  the  very 
general  adoi>tion  of  machinery  for  this  purpose. 

The  iti  U-st  ra  iyhteni  iKj  press  consists  of  a  massive  cast- 
iron  Iraine,  witli  a  projecting  stand  on  each  side  to  receive  the 
railway  bar;  on  the  top  revolves  a  large  shaft,  carrying  an  eccen- 
tric caiji,  which  acts  on  a  slider  moving  vertically  in  grooves  in 
the  large  frame  immediately  over  the  projecting  stand.  The 
bottom  of  the  slider  is  slightly  bevelled,  and  at  the  down  stroke 
reaches  to  within  four  or  live  inches  of  the  rail.  When  straight- 
ening, the  bar  rests  on  two  shallow  supports,  about  eighteen 
inches  apart,  on  the  stand,  the  convex  side  uj);  a  wedge-shaped 
key  is  carefully  inserted  under  the  slider,  so  that  at  the  lowest 
movement  the  slider  presses  on  the  rail  through  the  intervention 
of  the  key,  and  removes,  at  one  pressure,  part  or  whole  of  the 
convexity.  The  operation  is  repeated  until  all  irregularities  are 
taken  out.  If  the  benils  in  the  bar  are  very  short,  a  less  distance 
between  the  supports  is  dfmanded.  Considerable  delicacy  is 
required  in  using  the  tajierkey;  if  projected  too  far,  the  niil  may 
be  bent  in  the  reverse  direction,  or  completely  broken  if  made  of 
cold-short  iron.  Commonly  the  slider  moves  up  and  down  about 
thirty  times  in  a  minute,  t'lereby  enabling  skilful  workmen  to 
straighten  100  bars  daily  in  a  single  i)ress.  The  .stmin  thrown 
on  the  approaches  is  very  great,  and  renders  it  necessary  to  make 
the  whole  of  massive  projjortions. 

Frequently  the  bar.  after  leaving  the  straightener,  possesses  a 
degree  of  "winding"  or  twist,  which  is  detected  by  placing  the 
en. Is  on  two  planed  blocks  accurately  levelled  on  tlie  upjier  sur- 
f-M-c.  It  is  removed  by  grasping  the  ends  with  hmg  levers,  and 
applying  a  light  torsional  strain  until  the  desired  effect  is  pro- 
duced. 


Boiler-Plato  Iron. 

This  is  made  from  selected  No.  2  bar-iron,  when  a  superior 
quality  is  sought ;  but  tlie  larger  jiortion  of  the  jjivseiit  manu- 
facture is  rolled  direct  from  puddle), looms.  The  j)ile  for  best 
l)late  is  built  short  and  wide,  witli  an  e(jii;il  (piantity  of  pieces 
running  along  and  acro.-,s  it.  They  are  brougiit  toa  welding 
beat  in  a  reverberatory  furnace  of  the  ordinary  description,  and 
taken  to  the  plate-iron  rollers.  These  consist  of  two  pairs,  a 
slabbing  and  a  finishing,  both  of  a  plain  cylindrical  form,  chill<;d 
to  extreme  hardness  on  tiie  surface.  The  frames  in  which  the 
rollers  revolve  are  furnished  witii  large  tightening  screws  (six  or 
eight  inches  in  diameter  .  by  means  of  wliich  the  top  rollers  are 
screwed  <lown  or  i)ermit(ed  to  rise  at  jjleasure.  Commonly,  a 
Kystem  of  levers,  carrying  l,alance-weights,  is  api)ende<l  to  one  or 
both  top  rollers,  to  diminish  the  weiglit  on  the  otlier  rollers. 
The  c()Mi)ling  jiinions  connecting  tlie  (op  to  the  bottom  rollers 
are  frequently  dispensed  witli  in  rolling  thin  jilates. 

Tlic  short  Hat  pile  is  piissed  several  times  betwei-n  the  slabbing- 
rollers,  end  or  sidewise,  according  as  it  may  appear  to  rc((uire 


MANUFACTURE   OF    WUOUGHT   IRON.  87 

distention,  until  sufficiently  reduced  in  thickness  for  the  finish- 
ing-rollers, to  which  it  is  transferred  for  further  distention.  If 
the  iron  requires  it,  the  slab  is  reheated  aud  passed  between  the 
slabbing-roUers  a  second  time,  in  its  reduction  to  a  suitable 
thinness  for  the  finishing- rollers.  These  are  made  of  the  hard- 
est iron,  and  turned  to  glassy  smoothness  on  the  surface.  At 
first  its  direction  between  the  finishing-rollers  is  regu  ated  to 
supply  any  omission  in  the  slabbing  :  the  object  being  to  assimi- 
late its  horizontal  proportions  to  those  of  the  intended  plate. 
When  this  is  accomplished,  it  is  passed  successivclj-  in  the  same 
direction  until  the  desired  thinness  has  been  attained.  Metal 
gauges  of  the  length,  breadth,  and  thickness  of  the  plate,  indi- 
cate when  the  rolling  is  to  be  discontinued.  The  shearing  to 
the  exact  size  is  performed  on  the  cold  iron  by  powerful  lever- 
shears,  with  steel  knives  five  or  six  feet  long. 

The  ntanufacture  of  coininoii  boiler-plates,  ship- 
building plates,  and  much  of  the  inferior  descriptions  of  sheet- 
iron,  is  conducted  in  a  different  manner. 

•  Tlie  i> addle-hall  of  the  boiling  furnace  is  hammered  into 
a  flat  bloom,  two  of  which  are  placed  together  to  constitute  the 
plate  ;  when  cold,  they  are  charged  into  a  furnace,  heated  to 
melting,  slabbed,  and  rolled  in  the  foregoing  manner  to  the  de- 
sired thinness.  Plates  made  in  this  manner,  however,  oxight 
never  to  be  used  in  any  description  of  boiler  building.  A  very 
general  recourse  to  this  mode  of  manufacturing  has  unquestion- 
ably lowered  the  character  of  boiler-jilate  iron,  and  led  to  many 
fatal  explosions.  Good  boiler-jilates  should  not  break  with  a 
less  strain  than  twenty-five  tons  to  the  square  inch  of  metal  ;  but 
much  of  what  is  manufactured  for  the  purpose  will  not  bear 
more  than  two-thirds  of  this  strain. 


Nail  Rod  Iron. 

Nail  rods  are  manufactured  in  two  w.ij's  :  by  rolling  a  bar 
down  to  the  desired  section  ;  and  by  cutting  a  thin  strip  of  iron 
into  a  number  of  parallel  rods,  by  means  of  revolving  shears. 
The  first  metho  1  is  pursued  with  iron  for  horse-shoe  nails,  and 
the  superior  kind  of  rods,  forming  about  two  per  cent,  of  the 
manufacture  ;  and  the  shearing  with  the  remaining  ninety-eight 
per  cent. 

The  manufacture  by  shearing  strips,  is  known  in  the  trade  as 
slitting  nail  rods.  A  slitting-mill  consists  of  two  or  three  heat- 
ing furnaces,  a  pair  of  grooved  rollers  for  roughing  the  pile,  a 
pair  of  smooth  chillod-iron  rollers  for  flattening  it,  and  a  pair  of 
revolving  shears,  with  the  requisite  lever-cropping  shears.  Roll- 
ers and  shears  are  commonly  placed  in  parallel  lines,  seventeen 
or  eighteen  feet  apart  and  driven  at  nearly  the  same  number  of 
revolutions  per  minute  by  strong  spur-gearing.  The  shears  are 
formed  of  two  parts,  each  consisting  of  a  number  of  disks  of 
wrought  iron,  sixteen  or  seventeen  inches  diameter,  edged  with 
steel,  kept  the  requisite  distance  apart  by  other  disks  of  iron  of 
lesser  diameter  ;  the  whole  firmly  bolted  together,  and  mounted 


88  MANUFACTURE   OF   "WKOUGIIT   IRON. 

on  a  cast  or  ■wrought  iron  spindle.     When  revolving,  the  Tipper 
series  of  steeled  disks  project  into  the  spaces  of  the  lower  series, 
thus   forming  a  number  of  continuous  shearing  edges.     The 
depth  when  they  project  is  regulated  by  screw  bolts  attached  to 
the  cast-frames;   while  the  entrance  of  the  iron  to  be  shorn  is 
regulated  by  guides  and  plates,  similarly  adjusted  by  screw-bolts. 
Through  the  bottom  of  a  cistern  at  top,  a  shower  of  water  falls 
on  the  steel,  to  keep  it  from  softening  with  the  heat  of  the  bars. 
In  front  of  the   ai^paratus  a  wrought  iron  grated  frame  is  con- 
structed of  iron  bars,  to  receive  the  rods  delivered  by  the  shears. 
The  lit  ode  of  roUiiuj  may   be   described   thus  :    Two  or 
three  pieces  of  puddle-bar,  or  other  flat  iron,  are  placed  to  form 
a  low  pile,  which  is  brought  to  a  welding-heat  in  a  reverberatory 
furnace,  and  ti-ansferred  to  the  grooved  rollers.     In   these  it  is 
distended  to  a  bar  ten  or  twelve  feet  long,  by  three  and  a  half  or 
four  inches  wide,  and  of  a  thickness  proportionate  to  the  size  of 
the  intended  rod.     It  is  now  passed  between  the  smooth  rollers, 
so  as  to  reduce  it  to  the  precise  thickness,  and  at  the  same  time 
remove  anj'  roughness  on   the  face  of  the  iron.     It  is  now  of  a 
width  somewhat   less  than  the  breadth  of  the  upper  series  of 
steeled  disks  ;   and  on  insei-ting  one   end  of  the  strip  between 
the  guides,  it  is  drawn  on  by  the  revolving  shears,  and  cut  into 
as  many  rods  as  there  are  steeled  disks  in  its  width.     The  divid- 
ed rods  are  secured  on  light  hooks,  and  transferred  to  the  grat- 
ing.    The  strips  vary  slightly   in  width  ;   and  when  such  is  the 
case,  or  the  iron  is  of  a  weak  red-short  character,  a  number  of 
imperfect  rods  are  shorn  off  at  the  sides,  and  passing  aside  the 
guides,  require  constant  cleaning  from  the  apjiaratus. 

The  finished  rods  are  cut  to  length,  weighed  into  bundles, 
and  tied  up  by  twisting  around  them  three  or  four  small  bands 
of  hot  iron.  If  placed  in  stock,  or  in  carriages  for  conveyance  to 
purchasei-s,  great  care  should  be  taken  that  they  do  not  get  wet 
and  rusted  on  the  surface.  Kods  prepared  by  shearing  may 
readily  be  distinguished  from  rolled  rods  by  the'conca^■ity  of  the 
one  and  convexity  of  the  opposite  side;  the  other  two  sides  also 
show  the  cutting  action  of  the  shears,  and  two  edges  project 
slightly  with  minute  serrations. 

The  rapidity  with  which  nail-rods  are  produced  by  this  process 
is  perfectly  marvellous  to  the  uninitiated.  Working  on  the 
smaller  sizi's  of  rods,  a  mill  rolling  three  lengths  at  once,  as  is 
now  generally  done  in  the  largc^r  mills,  delivers  ninety  to  a  hun- 
dred rods  at  each  operation,  equal  to  the  continuous  delivery  of 
a  single  rod  through  the  week  at  a  velocity  of  ten  miles  per 
hour. 

Hoop-Iron  is  manufactured  from  small  piles  or  billets, 
rollcil  tirst  between  small  rollers  having  grooves  on  their  circum- 
ference, and  lastly  between  a  short  pair  of  hard  cylindrical 
rollfirs,  in  which  it  is  pressed  to  thf  width  and  tliickncss  dfsirrd. 
The  great  length  of  the  bars  juid  their  tcndenc^y  to  cool  (piicklj', 
renders  it  necessary  to  propel  the  grooved  rollers  at  very  high 
velocities;  but  the  smooth  pair  is  driven  at  the  more  usual 
spei'd  of  niiiity  or  a  hundriMl  revolutions  per  miuulo      This  puir 


MANUFACTURE   OF  WROUGHT  IRON.  89 

requires  to  be  exceeclinglj'  strong,  in  order  that  the  iron  may  be 
finished  comparatively  cold  and  thereby  carry  a  blue  face. 

Sniftll  jiatft,  squares,  bolts,  and  fine  irons  generally  are 
rolled  with  trains  having  three  rollers  in  height.  The  addition 
of  a  third  roller  to  each  set  expedites  the  rolling  one-half;  inas- 
much as  the  operation  is  continued  in  both  directions,  instead 
of  returning  the  bar  over  the  top  roller,  as  in  large  mills.  The 
rollers  are  commonly  eight  or  nine  inches  in  diameter  ;  the 
roughing  set  thirty  inches  long;  the  second  twenty-four,  and  the 
finishing  nine  inches  long  :  three  rollers  in  height,  instead  of 
the  two  in  other  mills.  A  speed  of  230  revolutions  i^er  minute  is 
common  and  preferable  to  slower  working;  at  this  velocity  the 
perii^hery  of  the  roller  moves  over  six  miles  per  hoiir;  and  calcu- 
lating the  several  movements  of  the  operatives  in  following  the 
bar  through  the  day,  it  is  seen  that  several  of  them  walk  more 
than  twenty  miles  daily  at  this  quick  rate. 

The  rolling  of  snuiU  flats  and  squares  in  such  trains  is 
conducted  on  principles  similar  to  those  pursued  in  larger  mills; 
but  the  round  iron  is  rolled  with  the  assistance  of  double  guides. 
Small  piles,  or  solid  pieces  o^  iron  termed  "  billets,"  are  roughed 
between  the  first  pair  of  rollers;  in  th3  second,  the  iron  is  first 
converted  to  a  square  and  then  into  a  bar  of  an  oval  section,  pre- 
cisely equal  in  area  to  that  of  the  intended  round  bar.  The 
grooves  in  the  short  finishing-rollers  (of  which  there  are  only 
two  in  rolling  rounds)  are  of  an  exact  semicircular  shape,  and  to- 
gether form  a  complete  circle.  The  oval  bar  is  presented  to 
these  rollers,  guided  in  a  vertical  direction  by  closely-fitting  iron 
blocks,  where  it  is  violently  compressed  to  a  perfectly  cylindri- 
cal form.  To  insure  this  being  done,  there  must  be  a  rigid  cor- 
respondence between  the  oval  and  circle.  If  the  oval  is  too 
small,  the  deficiency  of  metal  to  fill  the  circle  is  seen  in  the  flat- 
tened sides  of  the  latter;  if  too  large,  the  excess  of  metal  is  fre- 
quently forced  out  at  the  sides,  forming  thin  flanges.  If  the 
guides  fail  to  hold  the  bar  sufficiently  tight  to  prevent  its  turn- 
ing around,  the  bar  is  similarly  spoiled.  As  may  be  imagined, 
it  is  only  very  good  iron  that  will  stand  the  violent  alteration  of 
structure  wliea  comparatively  cold. 


90 


WEIGHT  OP   SQUARE  ROLLED   IRON. 
Weight  of  Square  Rolled  Iron. 

D-om  l-lG(h  Inch  to  ^  Inches. 

ONE  FOOT  IN  LENGTH. 


Weight. 


Side. 


Weight. 


Lbs. 

11.883 

13.52 

15.263 

17.112 

I'J.OGG 

21.12 

23.292 

25.56 

27.939 

30.416 

33.01 

35.704 

38.503 

41.408 

44.418 

47.534 


lUB. 

7 


Lbs. 

50. 756 
54.084 

57.517 
61.055 
64.7 
68.448 
72.305 
76.264 
80  333 
84.48 
88.784 
93.168 
97.657 
102.24 
106.95:1 
111.75G 


Side.       Weight. 


Ins. 


Lbs. 

116.671 

121.664 

132.04 

142  816 

154.012 

165.632 

177.672 

190.136 

203.024 

216.336 

230.068 

244.22 

258.8 

273.792 

289.22 

305.056 


Illustration. — What  is  the  weight  of  a  bar  IJ  ins.  bj'  12  inches 
in  leni:,'th? 

In  column  1st,  find  li  ;  opposite  to  it  is  7.604  lbs.,  which  is  7 
lbs.,  and  .004  of  a  lb.  If  the  lesser  denomination  of  ounces  is 
required,  the  result  is  obtained  as  follows  : 

]\[nltiply  the  remainder  by  16,  point  off  the  decimals,  and  the 
figures  remaining  on  the  left  of  the  point  give  the  number  of 
ounces. 

Thus,  .004  of  a  lb.  =  .004  X  16  =  9.664  =  7  lbs.  9.664  ounces. 
to  ascertain  the  weight  fob  less  than  a  foot  in  length. 


Operation.  Wliat  is  tiie  weight  of  a  bar  6  J  inches  square  and 
9|  inches  long? 

In  column  4th,  opposite  to  C)\,  is  132.04,  which  is  the  weight 
for  a  foot  in  length. 


6.25  X  12  inches 


=  132.04 


6.        "     is  .5  =   66.02 

3.        "     is  .5    of  6=    33.01 

.25     "      is    j^jOf3::::=       2.7508 


9.25 


=  101. 7808  pou7i(Z«. 


WEIGHT   OF   CAST   IRON   PIPES. 


91 


Weight   of  Round   Rolled   Iron. 

From  l-16ili  Inch  (o  12  Inches  in  Diameter. 

ONE  FOOT  IN  LENGTH. 


Diam. 

Weight. 

Diam. 

Weight. 

Diam. 
Ins. 

Weight. 

Diam. 

Weight 

lus. 

Lbs. 

Ins. 

Lbs. 

Lbs. 

Ins. 

Lbs. 

^"n 

.01 

\ 

1344 

1 

56.788 

1 

149.328 

h 

.041 

14.975 

I 

59.9 

J 

159.456 

^^ 

.093 

^ 

16.588 

1 

63  094 

8 

169.856 

.165 

'^ 

18.293 

5 

66  35 

\ 

180.696 

.373 

3. 

20.076 

i 

69.731 

191.808 

.663 

8 

21944 

k 

73.172 

a 

203.26 

n 

1.043 

3 

23.888 

3 

"8 

76.7 

9 

215.04 

-^ 

1.493 

J 

25.92S 

80.304 

} 

227.152 

i 

2.032 

i 

28.01 

84.001 

* 

239.6 

1 

2.654 

30.24 

a 

87.776 

f 

252.376 

j« 

3.359 

1 

32.512 

7 

91.634 

10 

265.4 

] 

4.147 

1 

34.881) 

6 

95.552 

\ 

278.924 

^ 

5  019 

I 

37.332 

1 

103.704 

292.688 

4 

5.972 

s 

38.864 

■g 

107.86 

4 

306.8 

5 

s 

7  01 

4 

42.464 

112.16 

11 

321.216 

^ 

8.128 

i 

45.174 

116  484 

\ 

336.004 

i 

9.333 

47  952 

i 

120.96 

h 

351.104 

2 

10.616 

^ 

50.815 

7 

130.048 

1 

366.536 

I 

11.988 

i 

53.76 

1 

4 

139.544 

12' 

382.208 

Weight  of  Cast  Iron  Pipes  of  different  Thicknesses. 

Froin  1  Inch  (0  24  Inches  in  Diameter. 

ONE   FOOT   IN    LENGTH. 


Weight. 


Piam. 

Thkn. 
Ins. 

Weight. 

!  Diam. 
Ins. 

Thkn. 
Ins. 

Ins. 

Lbs. 

1 

1 

3  06 

2f 

^ 

1 

5  05 

3 

H 

i 

3.67 

1 

6. 

1 

n 

6.89 

a 

n 

t 

8 

9.8 
7.8 

31 

I 

^ 

11.04 

a 

2 

"8 

8.74 

3h 

J 

12.23 

\ 

^ 

2J 

1 

9.65 

a 

^ 

13.48 

3f 

n. 

1 

10.57 

^ 

14.66 

2. 

1 

19.05 

1     4 

}> 

2a 

a 

11.54 

1 

Ft 

h 

15.91 

1 

£■ 

Lbs. 

20.59 

12.28 

17.15 

22. 15 

27.56 

18.4 

23.72 

29.64 

19.66 

25.27 

31  2 

20.9 

26.83 

33.07 

22.05 

28  28 

34.94 


Diam. 

Thkn. 

Weight. 

Ins. 

Ins. 

Lbs. 

H 

1 

23.35 

29.85 

1 

36.73 

^ 

i 

24.49 

1 

31.4 

a 

38.58 

^ 

1 

25.7 
32.91 

f 

40.43 

1  5 

* 

26.94 

1 

34.34 

a 

42.28 

5] 

h 

29.4 

4 

37.44 

f 

45.94 

6 

1 

31.82 

1 

40.56 

92  WEIGHT   OF    CAST   IRON    PIPES. 

Weight  of  Cast  Iron  Pipes.  — CoH/mued 


Diam. 

Ins, 
6 

6J 


n 


H 


n 


10 


lOJ 


Thkn. 


lUB. 


Weight. 


Lbs. 

49.6 

58.96 

34.32 

43.68 

5:13 

G3.18 

36.66 

46.8 

56.96 

67.6 

78.39 

39.22 

49.92 

60.48 

71.76 

83.28 

41.64 

52.68 

64.27 

76.12 

88.2 

44.11 

56.16 

68. 

80.5 

9:5.28 

46.5 

58.92 

71.7 

81.7 

97.98 

48.98 

62.02 

75.32 

88.98 

102.9 
51.46 
65.08 
78.99 
93.24 

108.84 
53.88 
6K.14 
82.68 
97.44 

112.68 
56.34 
71.19 


Diam.  Thkn 


Ins. 
11 

11^ 


12 


12i 


13 


13J 


14 


14i 


15 


15i 


Ins. 


Weight. 


11 
NoTK.  — ThcBo  wcighUdu  not  includoauy  allowaar  -lor  spigot  and  faucet  euus. 


Lbs. 
86.4 
101.83 
117.6 
58.82 
74.28 
90.06 
106.14 
122.62 
61.26 
77.36 
93.7 
110.48 
127.42 
63.7 
80.4 
97.4 
114.72 
132.35 
66.14 
83.46 
101  08 
118.97 
137.28 
68.64 
86.55 
104.76 
123.3 
142.16 
71.07 
89.61 
108.46 
127.6 
147.03 
73.72 
92.66 
112.1 
131.86 
151.92 
75.96 
'.15.72 
115.78 
136.15 
156.82 
78.4 
98.78 
119.48 
140.4 
161.82 


Diam. 


Ins. 
16 


16^ 


17 


17^ 


18 


19 


20 


21 


22 


U 


24 


Thkn. 


Ins. 


Weight. 


Lbs. 

80.87 
101.82 
123.14 
144.76 
166.6 
83.3 
104.82 
126.79 
149.02 
171  6 
85.73 
107.96 
130.48 
153.3 
176.58 
88.23 
111.06 
134.16 
157.59 
181  33 
114.1 
137.84 
161.9 
186.24 
120.24 
145.2 
170.47 
195.92 
126.33 
152.53 
179.02 
205.8 
132.5 
159.84 
187.6 
215.52 
138.6 
167.24 
196.40 
225.38 
144.  "^7 
174.62 
204.78 
235.28 
150.85 
181.92 
213.28 
245.00 


CAST   IRON   AND    COPPER.  93 

CAST  IRON. 
To  Compute  tho  Weight  of  a  Cast  Iron  Bar  or  Rod. 

Find  the  weight  of  a  wrought  iron  bar  or  rod  of  the  same  di- 
mensions in  the  preceding  tables  or  by  computation,  and  from 
the  weight  deduct  the  2-27th  part  ;  or, 

As  1000  :  .9257  :  :  the  weight  of  a  wrought  bar  or  rod  :  to  the 
weight  required.  Thus,  what  is  the  weight  of  a  piece  of  cast 
iron  4  X  3|  X  12  inches. 

In  table,  page  108,  the  weight  of  wrought  iron  of  these  dimen- 
sions is  50.692  lbs. 

Then  1000  :  .9257  :  :  50.692  :  46  93  lbs. 

To   Compute   tha   Weight    of  a  piece   of  Cast   or 
Wrought  Iron  of  any  Dimension  or  Form. 

By  the  rules  given  in  Mensuration  of  Solids,  ascertain  the 
number  of  cubic  inches  in  the  piece,  then  multiply  by  the 
weight  of  a  cubic  inch,  and  the  product  will  give  the  weight  in 
pounds. 

Example.— What  is  the  weight  of  a  cube  of  wrought  iron  10 
inches  square  by  15  inches  in  length  ? 

10  X  10  X  15  =  1500  cubic  inches. 

.2816  weight  of  a  cubic  inch.* 
422.4  pounds. 
2.  What  is  the  weight  of  a  cast  iron  ball  15  inches  in  diameter  ? 
Ball,  15  ins.  =176.7149  cubic  inches. 

.2607  weight  of  a  cubic  inch.  * 
460.6957  pounds. 


COPPER. 

To   Compute  the  Weight  of  Copper. 

Rule  — Ascertain  the  number  of  cubic  inches  in  the  piece  ; 
multiply  them  by  .32418,*  and  the  product  will  give  you  the 
weight  in  pounds. 

Example. — What  is  the  weight  of  a  copper  plate  ^  an  inch 
thick  by  16  inches  square  ? 
16-' =  256 

.5  for  I  an  inch 

l28X  .32418  =  41.495  pounds. 

Brazier's  Sheets  are  30  X  60  inches,  and  from  12  to  100  lbs. 
per  square  foot. 

Sheathing  Copper  is  14  X  48  inches,  and  from  14  to  34  oz.  per 
square  foot. 

*  The  weights  of  a  cubic  inch  as  here  give'.,  are  for  the  ordinary  metalH  ; 
when,  however,  the  spncific  gravity  of  the  metal  under  couHiileration  in  accu- 
rately known,  the  weight  of  a  cubic  inch  of  it  should  be  substituted  for  the 
units  here  given. 


94 


SHIP   AND   RAILROAD   SPIKES. 


LEAD. 

To   Compute  the  Weight  of  Lead. 

Rule. — Ascertain  the  number  of  cubic  inches  in  the  piece ; 
multiply  the  sum  by  .41015,  and  the  product  will  give  the 
weight  in  jwunds. 

Example. — What  is  the  weight  of  a  leaden  pipe  12  feet  long, 
3.75  inches  in  diameter,  and  1  inch  thick? 

By  Rule  in  I^Iensuration  of  Surfaces,  to  ascertain  the  Area  of 

Cylindrical  Rings. 

Area  of  (3.75  +  1  +  1)  =  25.9G7 
•'      "    3.75  =11.044 

Difference,  14.923,  or  area  of  ring. 

144  =12  feet. 

2148.912  X  .41015  =  8S1.37G  pounds. 


BRASS. 

To  Compute  the  Weight  of  Ordinary  Brass 

Castings. 

Rule. — Ascertiiin  the  number  of  cubic  inches  in  the  piece  ; 
multiply  them  by  .3112,  and  the  product  will  give  the  weight 
in  pounds. 


SHIP  AND  RAILROAD   SPIKES. 


Number  of  Iron  Spikes 

per 

100  lbs. 

-P 

.  C. 

Page. 

o 
.•4 

«-  S 

a. 
'3 

Batch   Nails 
1-4  iu.  sq're 

Ship  Spikes 

or 
Hatch  Nails 

5-16  in.  sq. 

Ship  Spikes 

or 
Beck  Nails 

3-8  in.  Bq're. 

Ship  Spikes 

7-16 
inch  square. 

Ship  Spikes 

1-2 
inch  square. 

Ship   Spikes 

9-16 
inch  square. 

Ship  Spikes 

5-8 
inch  square. 

Size 

No. 

Size 

No. 

Size 

No. 

Size 

No. 

Size 

No. 

Size 

No. 

Size 

No. 

in 

100 

in 

100 

in 

100 

in 

100 

In 

100 

in 

100 

iu 

100 

inc. 

lbs. 

inc. 

lbs. 

lUC. 

lbs. 

inc. 

lbs. 

inc. 

lbs. 

inc. 

lbs. 

Inc. 

lbs. 

3 

1900 

3 

1000 

4 

540 

!5 

340 

G 

220 

8 

140 

1" 

80 

3i 

1580! 

:n 

'JO 

4.1 

500 

5^. 

310 

04 

200 

9 

120 

15 

00 

4 

l.{2) 

4 

800 

5 

4(;o 

'  6 

300 

7 

190 

10 

110 

— 

- 

i\ 

1220' 

4.1 

6o;i 

r>\ 

420 

Ci 

280 

V, 

180 

11 

100 

— 

. 

b 

1020 

5 

580 

(1 

■100 

7 

2(iO 

8 

170 





. 

— 

— 

6 

520 

(Mf 

320 

7A 

210 

^ 

ICO 

— 



— 



— 

— 

— 

— 

— 

I  8 

220 

9 

150 









— 

— 

— 

— 

— 

— 

— 

— 

10 

140 

— 

— 

— 



Riiilnnid  Spikes  9-lGths  square  5i  inches  IGO  ])or  100  jnuinds. 
Riiilroud  Spikes  1-2  inch      '*      GJ       •'      2(.i0  jier  lOJ  pounds. 


COPPERS. 


95 


Burden's  Patent  Spikes  and  Horseshoes. 

Manufactured  at  the   Tkot    Ibon  and  Natl  Factoby,   Tkoy, 

New  Yoek. 


Boat  t-pikes. 

Ship  Spikes. 

Hook  He 

id. 

No.  in 
100  lbs. 

Horseshoes. 

Size  in    No.  in 
inches,    luo  lbs. 

Size  in 
inches. 

No.   in 
llO  lbs. 

800 
650 
437 
430 
421 
377 
275 
250 
174 
163 
155 
■  115 

Size    in 
inches. 

Size    in 
inches. 

No.    iu, 
100  lbs. 

3 

10 

1,750 
1,468 
1,257 
920 
720 
630 
497 
478 
362 
337 
295 
290 
210 
198 

4 

6.V 

7' 

I' 

8J 
9' 
10 

4  Xi 
4i  X  7-16 

5  Xi 

S'ixi 

5^  X  9-16 

6  X9-16 

6  Xf 

7  X9-10 

8  Xg 

555 
414 
252 
241 

187 
172    i 
138 

140    ' 

110    [ 

1 
2 
3 
4 

5 

84 
75 
65 
56 
39 

Coppers. 

Dimensions  and  Weujhifrom  1  to  208  Gallons. 


Inches 

Weight 

Inches 

Weight 

Inches 

lag 

Gallons 

in 

lag 

Gallons 

in 

lag 

Gallons 

to  brim. 

pounds 

1 

to  brim. 

pounds 

to  brim 

93 

1 

H 

24 

15 

22J 

29* 

29 

14 

2 

3 

24* 

16 

24 

30 

30 

14 

3 

4i 

25" 

17 

25^ 

32 

36 

15J 

4 

6 

25  i 

18 

27 

34 

43 

16^ 

5 

7J 

26 

19 

281 

35 

48 

17^ 

6 

9 

26J 

20 

30 

36 

53 

184 

7 

lOi 

26a 

21 

3U 

37 

58 

19i 

8 

12 

27 

22 

33 

38 

63 

20i 

9 

13i 

271 

23 

34J 

39 

67 

21 

10 

15 

27* 

24 

36 

40 

71 

2H 

11 

16i 

27| 

25 

37i 

45 

104 

22 

12 

18 

28 

26 

39" 

50 

146 

22i 

13 

191 

28  V 

27 

40* 

55 

208 

231 

14 

21 

29' 

28 

42" 

Weight 

in 
pounds 

43* 

45 

54 

64* 

72^ 

79  i 

87 

94^ 

100* 

106* 

156" 

219 

312 


Copper  Tubing. 

Weight  of  ihe  usual  thickness. 
When  the  inside  diameter  is  \  of  an  inch,  3  ozs. 
J  do  ,  6  ozs. ;  I  do.,  8  ozs. ;  |  do.,  10  ozs.  jjer  foot. 


I  do. 


5  ozs. ; 


96 


WEIGHT   OP   BEASS,    COPPER,   ETC. 
Brass,  Copper,  Steel,  and  Lead. 

Weight  of  a  Foot. 


1        BBASS. 

COPPER. 

STEEL. 

LEAD. 

Diamt'r 

Weight 

Weight 

Weight 

Weight 

Weight 

Weight 

Weight 

Weight 

aud  Side 

of 

of 

of 

of 

of 

of 

of 

of 

ofSq're. 

Round. 

Square. 

Round. 

Square. 

Round. 

Square., 

Round. 

Square. 

Inches. 

Lbs. 

Lbs. 

Lbs. 

Lbs. 

Lbs. 

Lbs. 

Lbs. 

Lba. 

'. . 

.17 

.22 

.19 

.24 

.17 

.21 

.  . 

.39 

.50 

.42 

.54 

.38 

.48 

. . 

.70 

.90 

.75 

.96 

.67 

.85 

.1 

1.10 

1.40 

1.17 

1.50 

1.04 

1.33 

1 

1.59 

2.02 

1.69 

2.16 

1.50 

1.91 

2.1G 

2.75 

2.31 

2.94 

2.05 

2.61 

1 

2.83 

3.  GO 

3.02 

3.84 

2.67 

3.41) 

3.87 

4  93 

IJ 

3.58 

45G 

3.82 

4,8G 

3.38 

4.34 

4.90 

6  25 

li 

4.4-2 

5.63 

4  71 

6. 

4.18 

5.32 

6.06 

7  71 

ll 

5.35 

6.81 

5.71 

7  27 

5  06 

6  44 

7  33 

9.33 

G.3G 

8.10 

6.79 

8.6J 

6  02 

7.67 

8.72 

11.11 

7.47 

9.51 

7.94 

10.15 

7.07 

9. 

10.24 

13.04 

if 

8.f.G 

11.03 

9.21 

11.77 

8.20 

10.14 

11.87 

15.12 

9.95 

12.G6 

10.  Gl 

13.52 

9.41 

11.98 

13.63 

17.30 

2 

11.32 

14.41 

12.08 

15.38 

10.71 

13.63 

15.51 

19.75 

2J 

12.78 

16.27 

13.G4 

17.36 

12.05 

15.80 

17.51 

22.29 

4 

14.32 

18.24 

15.29 

19.47 

13.51 

17.20 

19.63 

25. 

^ 

15.96 

20  32 

17.03 

21.69 

15.05 

19  17 

21.80 

27.80 

2A 

17.68 

22.53 

18.87 

24.03 

.  16.68 

21.21 

24.24 

30.86 

2 

i 

19.50 

24.83 

20.81 

26.50 

18.39 

23.41 

26.72 

34.02 

21.40 

27.25 

22.84 

29.08 

20.18 

25.70 

29.33 

37.34: 

23.30 

29.78 

24.92 

31.79 

22.06 

28.10 

32.05 

40.81 

3 

25  47 

32.43 

27.18 

34.61 

24.23 

30.60 

34.90 

44.44 

Stool. 
We'njhl  of  a  Foot  in  Length  of  Flat. 


Thick, 

Thick, 

Thick. 

Thict, 

Thick, 

Thick, 

Thick. 

Thick, 

Size. 

1-4  in. 

3-8tbB 

1-2  iu. 

S-8the. 

Size, 
in. 

1-4  iu. 

y-Hths. 

1-2  iu. 

5-8th8. 

in. 

Ib8. 

lbs. 

lbs. 

lba. 

lbs. 

lbs. 

IbH. 

lbs. 

.852 

1.27 

1.70 

2.13 

2.1 

2.13 

3  20 

4.26 

.5.32 

H 

.958 

1.43 

1.91 

2  39 

n 

2.34 

3.51 

4.68 

5.85 

1.06 

159 

2.13 

2. 66  1 

3 

2.55 

3.83 

5.11 

6.39 

1.17 

1.75 

2.34 

2.92  1 

:M 

2.77 

4.15 

5.53 

6  92 

1  1 

1.27 

1.91 

2.55 

3.19 ; 

■A 

2.98 

4.47 

r,.^H 

7.45 

1.49 

2.23 

2.98 

3.72 

3^} 

3.19 

4  79 

6.38 

7  98 

2 

1.70 

2.55 

3.40 

4.26 

4 

3.40 

5.10 

6.80 

8.52 

2i 

1.91 

2.87 

3H3 

4.79 

WEIGHT   OF    CAST   IRON,    COPPER,   ETC.  97 

Cast  Iron. 

Weight  of  a  Foot  in  Length  of  Flat  Cast  Iron. 


Width 

Thick, 

Thick. 

Thick. 

Thick, 

Thick, 

Thick, 

Thick. 

oflron 

l-4th    in. 

3-8ths  in. 

1-2  inch. 

5-8ths  in. 

3-4ths  in. 

7-8ths  in. 

1  inch. 

Inc's. 

Pounds. 

Pounds. 

Pounds. 

Pounds. 

Pounds. 

Pounds. 

Pounds. 

2 

1.56 

2.34 

3  12 

3.90 

4.68 

5.46 

6.25 

2i 

1.75 

2.63 

3.51 

4  39 

5.27 

6.15 

7.03 

2A 

1.95 

2.92 

3.90 

4.88 

5.85 

6.83 

7.81 

2f 

2.14 

3.22 

4.29 

5.37 

6  44 

7.51 

8  59 

3 

2  31 

3.51 

4.68 

5.85 

7.03 

8.20 

9.37 

H 

2.53 

3.80 

5.07 

6.34 

7.61 

8.88 

10.15 

3i 

2  73 

4.10 

5  46 

6.83 

8.20 

9.57 

10.93 

3f 

2  93 

4.39 

5.85 

7.32 

8.78 

10.25 

11.71 

4 

3.12 

4.08 

6  25 

7.81 

9.37 

10.93 

12.50 

4L 

3.32 

4.97 

6.64 

8.30 

9.96 

11.62 

13.28 

u 

3.51 

5.27 

7. 03 

8.78 

lit.  .54 

12.30 

14  06 

n 

3.71 

5.56 

7  42 

9.27 

11.13 

12.98 

14.84 

5 

3.90 

5.86 

7.81 

9.76 

11.71 

13  67 

15  62 

5^ 

4  10 

6.15 

8.20 

10.25 

12  30 

14.35 

16.40 

54 

4.29 

644 

8.59 

10  74 

12  89 

15.03 

17.18 

5^ 

4.49 

6.73 

8  98 

11.23 

13  46 

15  72 

17  96 

6 

4.68 

7.03 

9.37 

11.71 

14.06 

16  40 

18.75 

Cast  Iron,  Copper,  Brass,  and  Lead.  Balls. 

Weight  of  Cast  Iron,  Copper,  Brass,  and  Lead  BaUs,  fnmi  1  inch  to 
11  inches  in  diameter. 


Dia. 

C.  Iron. 

Copper. 

Brass. 

Lead. 

Dia. 
In. 

C.  Iron. 

Copper. 
Pounds 

Brass 
Pounds 

Lead. 

In. 

Pounds 

Pounds 

Pounds 

Pounds 

Pounds 

Pounds 

1 

.136 

.106 

.158 

.214 

7 

46.76 

57.1 

54.5 

73  7 

n 

.46 

.562 

.537 

.727 

7J 

57.52 

70.0 

67.11 

90.0 

2 

1.09 

1.3 

1.25 

1.7 

8 

69.81 

85.2 

81.4 

110.1 

91 

2.13 

2.60 

2.50 

3.35 

8h 

83.73 

102.3 

100.0 

l;i2.3 

3 

3.68 

4.5 

4.3 

5.8 

9 

99.4 

121.3 

115.9 

156.7 

H 

5.84 

7.14 

6.82 

9.23 

9h 

116  9 

143  0 

1.36.4 

184  7 

4 

8.72 

10.7 

10.2 

13.8 

10 

136.35 

166.4 

159.0 

215.0 

H 

12  42 

15.25 

14.5 

19.6 

lOh 

157.84 

193.0 

184.0 

250.0 

5 

17.04 

20.8 

199 

26.9 

11 

181.48 

221.8 

211.8 

286.7 

54 

22.68 

27.74 

26.47 

36.0 

lU 

207.37 

253.5 

242.0 

327.7 

6 

29.45 

35.9 

34.3 

46.4 

12 

235.62 

288.1 

275.0 

372.3 

6.^ 

37.44 

45.70 

43.67 

59.13 

98 


WEIGHT  OF  Cast  iron. 


Cast  Iron.- 

-WeirjUofa  Foot 

in  Length  of  Square  and  Round. 

SQUARE. 

KOUND. 

Size. 

Weight. 

Size. 
Inch. 

Weight. 

Size. 
Inch. 

Weight, 

Size. 
Inch 

Weight. 

Inch 

sq. 

Pounds. 

eq. 

Pounds. 

sq. 

Pounds. 

sq. 

Pounds. 

.78 

4| 

74.26 

8 

.61 

4| 

58.32 

1 

1.22 

5 

78.12 

.95 

5 

61.35 

'S 

1.75 

5J 

82.08 

1.38 

5J 

64.46 

2.39 

5i 

86.13 

B 

1.87 

51 

67.64 

3.12 

H 

90.28 

1 

2.45 

51 

70.09 

1| 

3.95 

4 

94.53 

H 

3.10 

4 

74.24 

1, 

4.88 

bl 

98.87 

H 

3.83 

4 

77.65 

1 1 

5.90 

4 

103.32 

i| 

4.64 

5^ 

81.14 

J.  i  ' 

7.03 

4 

107.86 

U 

5.52 

84.71 

1  ' 

8 

8.25 

6 

112.50 

l| 

6.48 

6 

88.35 

1 3. 

9.57 

«1 

122.08 

l| 

7.51 

64^ 

95.87 

10.98 

4 

6| 

132.03 

1 

8.62 

4 

103.69 

2 

12.50 

142.38 

2 

9.81 

111.82 

2J 

14.11 

7 

153.12 

n 

11.08 

7 

120.26 

2i 

15.81 

n 

164.25 

2i 

12.42 

7\ 

129. 

21 

17.62 

74 

175.78 

21 

13.84 

H 

138.05 

24 

19.53 

n 

187.68 

2| 

15.33 

71 

147.41 

2| 

21.53 

8 

200. 

2| 

16.91 

8' 

157.08 

21 

2;^.  63 

8.V 

212.56 

2| 

2| 

18.56 

8\ 

167.05 

2| 

25.83 

8i 

225.78 

20.28 

8, 

177.10 

3 

28.12 

^ 

239.25 

3 

22.08 

n 

187.91 

3J 

30.51 

9 

253. 12 

^ 

23.96 

9' 

198.79 

3i 

33. 

9| 

267.38 

^ 

25.SI2 

n 

210. 

31 

35  59 

94 

282. 

n 

27.95 

9.i 

221.50 

^1 

38.28 

-n 

297.07 

'.n 

30.06 

91 

233  31 

41.06 

10 

312. 5t) 

3| 

32.25 

10 

245.43 

3| 

43.94 

10.1 

328.32 

31 

34.51 

H'i 

257  86 

3} 

40.92 

lo.l 

314.53 

3  J 

30.85 

lOA 

270.59 

4 

50. 

\()\ 

361.13 

4 

39.27 

m 

283.63 

44 

53.14 

11 

378.12 

H 

41.76 

11 

296.97 

^ 

56.44 

ll.i 

395.50 

4 

44.27 

11] 

310.63 

n 

59.81 

111 

413.28 

n 

46.97 

lU 

321.. 59 

63.28 

11] 

431.44 

M 

49.70 

11:] 

338  85 

66.84 

12 

450. 

4 

52.50 

12 

353.43 

4:{ 

70  50 

5.5.37 

Cast  Iron. —  We'ujM  of  a  Suj>e'ficial  Fool  from  \  in  2  inches  thick. 


Size. 

Weight 

Size. 

Weight.' 

Size. 

IllH. 

Weight. 

Size. 
Ids. 

Weight. 

Size. 

Weight. 

Ihb. 

PouudH 

IDB. 

Pounds 

PouiuIh 

PouiuIh 

Ina. 

Pounds 

. 

9.37 

fr 

23.43 

1 

:t7.50 

n 

51.56 

1? 

li- 

65.62 

. 

14.06 

28.12 

u 

42.18 

u 

56.25 

70.31 

18.75 

I: 

32.81 

n 

46.87 

n 

60.93 

2 

75. 

WEIGHT    OF    BOILER   TUBES. 


99 


To  Ascertain  the  "Weight  of  Wrought  Iron,  Copper, 
or  Brass  Tubes  and  Pipes  per  Lineal  Foot. 

From,  \  an  Inch  in  Inttrnal  Diameter  to  6  Inches. 


Area  of 

Area  of 

Area  of 

Area  of 

Diam. 

Plate. 
Sq.  Feet. 

Diam. 

Plate. 
Sq.  Feet. 

Diam. 

Plate. 
Sq.  Feet. 

Diam. 

Plate. 

Ins. 

Ins. 

Ins. 

Ins. 

Sq.  Feet. 

^ 

.1309 

15-16 

.3436 

2J 

.7199 

4.^ 

1.1781 

9-16 

.1473 

If 

.36 

2i 

.7526 

4| 

1.2108 

f 

.1636 

1  7-16 

.3764 

3 

.7854 

4f 

4| 

1.2435 

11-16 

.18 

u 

.3927 

3^ 

.8181 

1.2763 

3-4 

.1964 

1| 

.4254 

31 

.8508 

5 

1.309 

13-16 

.2127 

1| 

.4581 

3| 

.8836 

H 

1.3417 

i 

.2291 

H 

.4909 

3k 

.9163 

4 

1.3744 

15-16 

.2454 

2 

.5236 

n 

.949 

4 

14072 

1 

.2618 

2^ 

.5543 

3| 

.9818 

H 

1.4399 

11-16 

.2782 

2Jr 

.587 

4 

1.0472 

5| 

1.4726 

u 

.2945 

•2| 

.6198 

•  H 

1.0799 

5| 

1.5053 

13-16 

.3105 

2i 

.6545 

4.V 

1.1126 

5| 

1.5381 

U 

.3272 

2| 

1 

.6872 

H 

1.1454 

6 

1.5708 

Application  of  the  Table. 

When  the  Thickness  of  the  Metal  is  given  in  the  Divisions  of 

AN  Inch. 

To  the  internal  diameter  of  the  tube  or  pipe  add  the  thickness 
of  the  metal  ;  take  the  area  of  a  plate  in  square  feet,  from  the 
table,  for  a  diameter  equal  to  the  sum  of  the  diameter  and  thick- 
ness of  the  tube  or  pipe,  and  multiply  it  by  the  weight  of  a 
square  foot  of  the  metal  for  the  given  thickness,  and  again  by- 
its  length  in  feet. 

Illustkation. — Required  the  -weight  of  10  feet  of  copper  tube 

1  inch  in  circumference  and  I  of  an  inch  in  thickness. 

1  -|- 1  =  1^  =  .2945  square  feet  for  1  foot  of  length. 
Weight  of  1  square  foot  of  copper^  of  an  inch  in  thickness 
=  5.781  lbs.;  then,  .2945  X  5.781  =  1.7025  lbs. 

When  the  Thickness  of  the  Metal  is  given  in  Numbees  of  a 

WiEE  Gauge. 

To  the  internal  diameter  of  the  tube  or  pipe  add  the  thickness, 
multiply  the  sum  by  3.1416,  divide  the  product  by  12,  and  the 
quotient  will  give  you  the  area  of  the  plate  in  square  feet.  Then 
proceed  as  before  given. 

Illttstration.  -Required  the  weight  of  10  feet  of  coi^per  pipe 

2  inches  in  diameter,  and  No.  2  American  wire  gauge  in  thick- 

I16SS 

2  +  .25763  X  3.1416  —  12  =  2.25763  X  3.1416  -^  12  =  .591   square 
feet ;  then,  .591  X  11.G706  =  G.b97  lbs 


100       SIZE   AND   WEIGHT   OF   LEAD   PIPE,  ETC. 

Table  showing  the  Thickness  and  Weight  of  Gal- 
vanized Sheet  Iron. 

Dimensions  of  Sheet,  2  Feet  tN  Width  by  from  G  to  9  Feet 

IN  Length. 


Wire 
Gauge. 

Weight 

per 

Sq.    loot. 

Oz. 

Wire 
Gauge. 

Weight 

per 

Sq.    Foot. 

Wire 

Gauge. 

Weight 

per 

Sq.   Foot. 

Oz. 

Wire 
Gauge. 

Weight 

per 

Sq.   Foot. 

No. 

No. 

Oz. 

No. 

No. 

Oz. 

30 

10 

26 

15 

22 

21 

18 

37 

29 

11 

25 

10 

21 

24 

17 

43 

28 

12 

2i 

17 

20 

28 

16 

48 

27 

14 

23 

19 

19 

33 

U 

60 

Patent    Improved    Lead    Pipe,   Sizes    and   "Weight 

per  ^Poot. 


J2 

<3 


In. 


Weight 
Per  Foot 

lU 

d 

In. 

il 

fe      (0 

2 

i 

lbs.  oz. 

lbs.  oz. 

In. 

lbs.  oz. 

6 

1 
•> 

1     4 

^ 

1     4 

8 

i  i 

1     8 

2     0 

10 

it 

2     0 

2     4 

12 ; 

•  i 

3     0 

2     8 

1     0 

r? 

8 

13 

3     0 

1     8 

n 

1     0 

4    0 

8 

i  i 

1     8 

1 

1     8 

10 

i  ( 

2     0 

1  12 

12 

( ( 

2  12 

2     0 

14 

^ 

12 

2     8 

1     0 

4. 

14 

3     0 

o5 

-s  "S 

i      1 

■a  o 

4 

^ 

.2f  h 

XI 

6 

6 

In. 

lbs.  oz. 

In. 

1 

4     0 

IJ 

ii 

6     0 

1^ 

n 

t  k 

2  8 

3  0 

2 

it 

3     8 

t( 

ti 

4     0 

•41 

M 

it 

5     0 

3 

_o 

n. 

3     0 

3^ 

^ 

•w 

a 

3     8 

4 

fl 

t( 

4     0 

H. 

w~1 

t  ( 

4     8 

0 

f^ 


^ 


lbs.  oz. 

5  0 

4  0 

5  0 

6  0 

7  0 
11  0 
13  0 
15  0 
18  0 
20  0 
22  U 


Boston  Lead  Pipe,  Sizes  and  Weight  per  Foot. 


>iln. 

Kin. 

%ln. 

1  In. 

l^ 

in. 

l«In. 

IX  in. 

3  in. 

lbs. 

oz.  1 

Ibe. 

1 
oz 

lbs. 

oz. 

IbH. 

oz. 

lbs. 

oz.  ' 

lbs. 

oz. 

lbs. 

oz 

IbH 

oz. 

10  1 

2 

12 

1 

1 

1 

8 

2 

4 

3 

5 

3 

10 

4 

12 

12 

3 

1 

6 

1 

12 

2 

8 

3 

12 

4 

3 

5 

8 

13 

1 

12 

2 

2 

13 

4 

4 

5 

2 

7 

12 

1 

4 

2 

4 

2 

G 

3 

3 

4 

10 

1 

8 

3 

2 

2 

11 

3 

15 

6 

1 

11 

3 

14 

:) 

13 

i 

1 

14 

5 

2 

4 

6 

4 

STRENGTH    OP    MATERIALS. 


101 


Slieet  Lead.— Weight  of  a  Square  Foot,  21,  3,  3^,  4,  ^,  5,  G, 
7,  8^,  9,  10  lbs.  and  upward. 


Comparative  Strength  and   Weight  of  Ropes  and 

Chains. 


a 
o 

Cm      ^ 

u 

s 


4i 


5| 

6i 

7 

8 

8| 

9i 


03 

o  ^ 

.1 

ft  d 

d      o 
2 

.^      T-l 

J3     -d 

o    ■=< 

o  d 

■aa 

oj  d  d 

a -2 

^1 

^1 

2    1 

d  d 
Q 

2| 

5 

^. 

1    51 

10 

4| 

s 

8 

1  161 

10| 

5| 

y'n 

10^ 

2  10 

in 

7 

14 

3    51 

12i 

9| 

T^n 

18 

4    31 

13 

Hi 

# 

22 

5     2 

133- 

15 

11 
i  6 

27 

6    41 

14% 

19 

II 

32 

7    7 

15i 

21 

\l 

37 

8  135 

16' 

Note. — It  must  be  understood  and  also  borne  in  mind,  that, 
in  estimating  the  amount  of  tensile  strain  to  which  a  body  is 
subjected,  the  weight  of  the  body  itself  must  also  be  taken  into 
account ;  for  according  to  its  position  so  may  it  approximate  to 
its  whole  weight  in  tending  to  produce  extension  within  itself; 
as  in  the  almost  constant  application  of  ropes  and  chains  to  great 
depths,  considerable  heights,  &c. 


STRENG-TH    OF    MATERIALS    OF 
CONSTRUCTION. 


Materials  of  construction  are  liable  to  four  different  kinds  of 
strain  ;  viz.,  stretching,  crushing,  transverse  action,  and  torsion 
or  twisting  ;  the  first  of  which  depends  upon  the  body's  tenacity 
alone  ;  the  second,  on  its  resistance  to  compression  ;  the  third, 
on  its  tenacity  and  compression  combined  ;  and  the  fourth,  on 
that  property  by  which  it  opposes  any  acting  force  tending  to 
change  from  a  straight  line,  to  that  of  a  spiral  direction,  the  fibres 
of  which  the  body  is  composed. 

In  bodies,  the  power  of  tenacity  and  resistance  to  compression, 
in  the  direction  of  their  length,  is  as  the  cross-section  of  their 
area  multiplied  by  the  results  of  experiments  on  similar  bodies, 
as  exhibited  m  the  following  tables. 


102 


BTRENGTH   OP   MATERIALS. 


Table  showing  the  Tenacities,  Resistances  to  Com- 
pression, and  other  Properties  of  the  common 
Materials  of  Construction. 


Names  of  Bodies. 


Absolute 


Ash, 

Beech, 

Brass, 

Brick, 

Cast  Iron 

Copper  (wrought), 

Elm, 

Fir,  or  Pine,  White,  . 

»♦  "      Red,  . . . 

"  "      Yellow, 

Granite  (Aberdeen), 
Gun-metal  (copper  8, 

and  tin  1 ),    

Malleable  Iron 

Larch, 


Tenacity 

in  lbs.   per 

eq.  Inch. 


Lead 

Mahogany,  Honduras 

Marble, 

Oak, 

Eope(  1  in.  in  circum. ) 

8teel, 

Stone,  Bath, 

"        Craigleith, .  . . 

"        Dundee, 

"        Portland,  . . .  . 

Tin  (cast),    

Zinc  (sheet), 


14,130 
12,225 
17,908 
275 
13,434 
33,000 
9,720 
12,340 
11,800 
11,835 


35,838 

56,000 

12,240 

1,824 

11,475 

551 

11,880 

200 

128,000 

478 

772 

2,001 

857 

4,730 

9,120 


Uebistance 
to   coinpreB- 
BioQ   lu    lbs 
per  eq.  iucti. 


Compared  \,  ith  Cast  Iron 


8,548 

10,304 

562 

86,397 

1,033 
2,028 
5,375 
5,445 
10,910 


5,508 

8,000 
6,000 
9,504 


5,490 
6,630 
3,729 


Its 
strength 


0.23 
0.15 
0.435 

LO 

0.21 
0.23 
0.3 
0.25 


0.65 

1.12 

0.136 

0.096 

0.24 

0.25 


Its  ex- 

tL'Dsibility 
is 


0.182 

0.365 


2.6 
2.1 
0.9 

1.0 

2.9 
2.4 
2.4 
2.9 


1.25 

0.86 

2.3 

2.5 

2.9 

2.8 


IIS 

stiffness 
Is 


0.089 
0.073 
0.49 

1.0 

0.073 
0.1 
0.1 
0.087 


0.535 

1.3 

0.0585 

0.038 

0.487 

0.093 


0.75 
0.5 


0.25 
0.76 


Resistance    to    Lateral    Presstire,    or    Transverse 

Action. 

The  strength  of  a  square  or  retangular  beam  to  resist  lateral 
pressurfi,  acting  in  a  perpendicular  direction  to  its  leugtli,  is  as 
the  breadth  and  Sfpiarc  f)f  the  depth,  and  inversely  a,s  the  length; 
thus,  a  briiiii  twic.' llK-br.'adthnfaiiotlicr,  all  other  circumstaneeH 
being  alike,  eqnids  twi(!((  the  strength  of  tlie  other;  or  twice  tho 
depth  e<iuals  four  times  the  stnngth,  and  twicr  the  length  equals 
only  half  the  strength,  Ac,  according  to  tho  rule. 


STRENGTH   OP   MATERIALS. 


103 


Table  of  Data,  containing  the  EesTilta  of  Experi- 
ments on  the  Elasticity  and.  Strength  of  various 
Species  of  Timber,  by  Mr.  Barlow. 


Species  of 
Timber. 


Teak 

Poona . . 

English  Oak .  . 
Canadian  "  . . 
Dantzic  "  . . 
Adriatic     "    . 

Ash 

Beech. 


Value  of 

Value  of 

E. 

S. 

174.7 

2,462 

122.26 

2,221 

105. 

1,672 

155.5 

1,766 

86.2 

1,457 

70.5 

1,38.3 

119. 

2,026 

98. 

1,556 

Species  of 
Timber. 

Elm 

Pitch  Pine  . . 
Red  Pine. .  . 
New  Engl'd  Fir 

Riga  Fir 

Mar  Forest  Fir. 

Lai'ch . 

Norway  Spruce 


Value  of 

E. 

50.64 

8S.68 

133. 

158.5 

90. 

63. 

76. 

105.47 

Value  of 
S. 


1,013 
1,632 
1,341 
1,102 
1,100 
1,200 
900 
1,474 


To  find  the  dimensions  of  a  beam  ccqxihle  of  sitskdning  a  gicen  weight, 
with  a  given  degree  of  deflection,  xchen  supported  at  both  ends. 

Rule. — Multiply  the  weight  to  be  siipported  in  lbs.  by  the 
cube  of  the  length  in  feet;  divide  the  product  bj'  32  times  the 
tabular  value  of  E,  multii:)lied  into  the  given  deiiection  m  inches; 
jind  the  quotient  is  the  breadth  multiplied  by  the  cube  of  the 
depth  in  inches. 

Note  1. — When  the  beam  is  intended  to  be  square,  then  the 
fourth  root  of  the  quotient  is  the  breadth  and  depth  required. 

Note  2.  —If  the  beam  is  to  be  cylindrical,  multiply  the  quo- 
tient by  1.7,  and  the  fourth  root  of  the  product  is  the  diameter. 

Ex. — The  distance  between  the  su^Dports  of  a  beam  of  Riga  fir 
is  16  feet,  and  the  weight  it  must  be  capable  of  sustaining  in  the 
middle  of  its  length  is  8,000  lbs.,  with  a  deflection  of  not  more 
than  I  of  an  inch;  what  must  be  the  depth  of  the  beam,  suppos- 
ing the  breadth  8  inches  ? 

^^  ^  ^°^^     =  15175  —  8  =  3  v/ 1897  =  12.35  in.,  the  depth. 
9JX32X.75  •  ^  .  i- 

To  determine  the  absolute  strength  of  a  rectangular  beam  of  limber,  when 
supported  at  both  ends,  and  loa  led  in  the  middle  of  its  length,  as  beams 
in  general  ought  to  be  calcidated  to,  so  that  they  may  be  rendered  capa- 
ble of  withstanding  all  accidental  cases  of  emergency. 

Rtjle.  —Multiply  the  tabular  value  of  S  by  4  times  the  depth 
of  the  beam  in  inches,  and  by  the  area  of  the  cross-section  in 
inches;  divide  the  product  by  the  distance  between  the  supports 
in  inches,  and  the  quotient  will  be  the  absolute  strength  of  the 
beam  in  lbs. 

Note  1. — If  the  beam  be  not  laid  horizontally,  the  distance  be- 
tween the  supports,  for  calculation,  must  be  the  horizontal  dis- 
tance. 


104  STRENGTH    OF   MATERIALS. 

Note  2. — One-fourth  of  the  weight  obtained  by  the  rule  is  the 
greatest  weight  that  ought  to  be  applied  in  practice  as  permanent 
load. 

Note  3. — If  the  load  is  to  be  applied  at  any  other  point  than 
the  middle,  then  the  strength  will  be  as  the  product  of  the  two 
distances  is  to  the  square  of  half  the  length  of  the  beam  between 
the  supports;  or,  twice  the  distance  from  one  end,  multiplied  by 
twice  from  the  other  and  divided  by  the  whole  length,  equals 
the  effective  length  of  the  beam. 

Ex.— In  a  building  18  feet  in  width,  an  engine  boiler  of  5 J 
tons  (2,24i)  lbs.  to  a  ton)  is  to  be  fixed,  the  centre  of  which  is  to 
be  7  feet  from  the  wall,  and  having  two  pieces  of  red  pine,  10 
inches  by  6,  which  I  can  lay  across  the  two  walls  for  the  piirpose 
of  slinging  it  at  each  end, —may  I,  with  sufficient  confidence,  ap- 
ply them  so  as  to  effect  this  object? 

2240  X  5.5  — 2  =  6U;0  lbs.  to  carry  at  each  end. 
And  18  feet  —  7  =  11.  double  each,  or  U  and  22,  then  14  X  22 
-^  18  =  17  feet,  or  204  inches,  effective  length  of  beam. 

'Tabular  value  of  S,  red  pine,  =  1341  X  4  X  10  X  (JO-i-204  = 
15,776  lbs.,  the  absolute  strength  of  each  piece  of  timber  at  that 
point.  * 

To  determine  the  dimensions  of  a  rectangular  beam  capable  of  supporting 
a  required  weight,  wUh  a  given  degree  of  deflection,  wlwnflxed  at  o/ie 
end. 

RtTLE. — Divide  the  weight-  to  be  supported,  in  lbs.,  by  the 
tabular  value  of  E,  multii)lii(l  by  the  breadth  and  deflection, 
both  in  inches,  and  the  cube  root  of  the  quotient,  multiplied  by 
the  length  in  feet,  ee^uals  the  depth  recjuired  in  inches. 

Ex. — A  beam  of  ash  is  intended  to  bear  a  load  of  700  lbs.  at  its 
extremity,  its  length  being  5  feet,  breadth  4  inches,  and  the  de- 
flection not  to  exceed  i  an  inch. 

Tabular  value  ofE^  119  X  4  X  -5  ^  238  the  divisor; 

then  700 -i-  238  =?»  y  2.1)4  X  5  =  7.25  inches,  depth  of  the  beam. 

To  find  the  absolute  strength  of  ar  ctnngtdar  beayn,  lohen  fixed  at  one  end 
ami  loaded  at  the  other. 

Rule. — Multiply  the  value  of  S  by  the  depth  of  the  Ix^am  and 
by  the  area  of  its  section,  both  in  inches;  divide  the  ])roduct  by 
the  leverage  in  inches,  and  the  (^tiotient  equals  the  absolute 
strength  of  the  beam  in  lbs. 

Ex. — Abeam  of  Riga  fir,  12  inches  by4J,  and  projecting  6i 
feet  from  the  wall;  what  is  the  greatest  wciglit  it  will  support  at 
the  extntnity  of  its  hngtliV 

Tabular  vabie  of  S  =  1 100.     12  X  4.5  -_-  CA  sectional  area. 
Then  llO:)  X  12  X  54-^78  =  9138.4  lbs. 

When  friujture  of  a  brum  is  jnodueed  by  vertical  pressure,  the 
fi})res  of  Mk;  lower  section  of  frac^ture  are  separated  by  extension, 
whilst  at  till!  same  time  those  t)f  the  uj)p(!r  j)()rtion  are  destroyed 
by  compression;   Lenco  exists  a  point  in  section  where  neither 


STRENGTH   OF   MATERIALSi  105 

the  one  nor  the  other  takes  place,  and  which  is  distinguished  as 
the  point  of  neutral  axis.  Therefore,  by  the  law  of  fracture  thus 
established,  and  i)roper  data  of  tenacity  and  compression  given, 
as  in  the  preceding  table,  we  are  enabled  to  form  metal  beams  of 
strongest  section  with  the  least  possible  material.  Thus,  in  cast 
iron,  the  resistance  to  compression  is  nearly  as  6J  to  1  of  tenaci- 
ty, consequently  a  beam  of  cast  iron,  to  be  of  strongest  section, 
must  be  a  parabola  in  the  direction  of  its  length,  the  quantity  of 
material  in  the  bottom  flange  being  about  6J  times  that  of  the 
upper.  But  such  is  not  the  case  with  beams  of  timber;  for  al- 
though the  tenacity  of  timber  be  on  an  average  twice  that  of  its 
resistance  to  compression,  its  flexibility  is  so  great  that  any  con- 
siderable length  of  beam,  where  columns  cannot  be  situated  to 
its  siipport,  requires  to  be  strengthened  or  trussed  by  iron  rods. 
And  these  applications  of  princiijle  not  only  tend  to  diminish 
deflection,  but  the  required  purpose  is  more  effectively  attained, 
and  that  by  lighter  pieces  of  timber. 

To  ascertain,  the  absolute  sirnvjth  of  a  cast  iron  beam  of  the  preceding 
form,  or  that  of  strongest  section. 

BuLE. — IMultiply  the  sectional  area  of  the  bottom  flange,  in 
inches,  by  the  depth  of  the  beam  in  inches,  and  divide  the  pro- 
duct by  the  distan-ce  between  the  supports,  also  in  inches;  and 
514  times  the  qiiotient  eqiial  t'le  absolute  strength  of  the  beam 
in  cwts. 

The  strongest  form  in  which  any  given  quantity  of  matter  can 
be  disposed  is  that  of  a  hollow  cylinder;  and  it  has  been  demon- 
strated that  the  maximum  of  strength  is  obtained  in  cast  iron, 
when  the  thickness  of  the  annulus  or  ring  amounts  to  one-fifth 
of  the  cylinder's  external  diameter;  the  relative  strength  of  a 
solid  to  that  of  a  hollow  cylinder  being  as  the  diameters  of  their 
sections.     (See  Tables.) 


Kesistanee  of  Bodies  to  Flexure  by  Vertical 
Pressure. 

When  a  piece  of  timber  is  employed  as  a  column  or  support, 
its  tendency  to  yielding  by  compression  is  difi'erent  according  to 
the  jiroportion  between  its  length  and  area  of  its  cross-section; 
and  supposing  the  form  that  of  a  cylinder  whose  length  is  less 
than  seven  or  eight  times  its  diameter,  it  is  impossible  to  bend 
it  by  any  force  applied  longitudinally,  as  it  will  be  destroyed  by 
splitting  before  bending  can  take  place  ;  but  when  the  length 
exceeds  this,  the  column  will  bend  under  a  certain  load,  and  be 
ultimately  destroyed  by  a  similar  kind  of  action  to  that  which 
has  place  in  the  transverse  strain.  Columns  of  cast  iron  and  of 
other  bodies  are  also  similarly  circumstanced. 

When  the  length  of  a  cast  iron  column  with  flat  ends  equals 
about  thirty  times  its  diameter,  fracture  will  be  produced  wholly 
by  bending  of  the  material.  When  of  less  length,  fracture  takes 
place  partly  by  crushing  and  partly  by  bending.  But  when  the 
column  is  enlarged  in  the  middle  of  its  length  from  one  and  a 

5* 


106 


STRENGTH   OF   MATERIALS. 


half  to  twice  its  diameter  at  the  ends,  by  beiii<;  cast  hollow,  ths 
strength  is  greater  by  one-seventh  than  in  a  solid  column  con- 
taining the  same  quantity  of  material. 


Table, 

Showing  the  Weight  or  Peessure  a  Beam  of  Cast  Iron,  1  inch 
IN   breadth,  will   sustain,  without   destroying  its   elastic 

FORCE,  when  it  IS  SUPPORTED  AT  EACH  END  AND  LOADED  IN  THE 
MIDDLE  OF  ITS  LENGTH,  AND  ALSO  THE  DEFLECTION  IN  THE  MIDDLE 
WHICH  THAT  WEIGHT  WILL  PRODUCE.  Uy  Mr.  HoDGKINSON,  MAN- 
CHESTER. 


L'gth. 

6  feet. 

7  feet. 

8  feet 

9  feet. 

10  feet. 

Depth 

Weigbt 

Ded. 

Wci^'ht 

Detl. 

Weight 

Defl. 

Weight 

Uefl 

Weight 

Defl. 

in  iu. 

iu  lbs. 

m  lu 
.24 

iu  lbs. 

Ill  in. 
.33 

lu  lbs. 

in  in. 
.426 

in  lbs. 

lU  lU. 

in  lbs. 

in  in. 

3 

1,278 

1.0S9 

954 

855 

.54 

765 

.66 

3i 

1,739 

.205 

1,482 

28 

1,298 

.305 

1,164 

.46 

1,041 

.57 

4' 

2,272 

.18 

1,9.50 

.245 

1,700 

.32 

1,520 

.405 

1,360 

.5 

4i 

2.875 

.1(5 

2,450 

.217 

2,146 

.284 

1,924 

.36 

1,721 

.443 

5* 

3,560 

.141 

3,0-;0 

.196 

2,650 

.256 

2,375 

.32 

2,125 

.4 

6 

5,112 

.12 

4  3:)G 

.103 

3,816 

.213 

3,420 

.27 

3,0(50 

.33 

7 

G,958 

.103 

5  9J9 

.14 

5,194 

.183 

4,655 

.2  5 

4.105 

.29 

8 

9,088 

.09 

7,744 

.123 

6,781 

16 

6,080 

.203 

5,440 

.25 

9 

9,801 

.109 

8,580 

.112 

7,695 

.18 

6,885 

.22 

10 

12,100 

.09K 

10,600 

.128 

9,500 

.162 

8,500 

.2 

11 

12,82(; 

.117 

11,495 

.15 

10,285 

.182 

12 

15,204 

.107 

13,680 

.135 

12,240 

.17 

13 

16,100 

.125 

14.400 

.154 

14 

18,(500 

.115 

16,700 

.143 

12  feet. 

U  feet. 

16  feet. 

18  feet. 

20  fe 

et 

6 

2,548 

.48 

2,184 

.65 

1,912 

.H5 

1,(599 

1.08 

1,.530 

1.34 

7 

3,471 

.41 

2,975 

..58 

2,603 

.73 

2,314 

.93 

2,082 

1.14 

8 

4,532 

.3(1 

3,.S81 

.49 

3.39(5 

.04 

3,020 

.HI 

2,720 

1.00 

9 

5,733 

.32 

4,914 

.44 

4,302 

.57 

3,825 

.72 

3.4,38 

.89 

10 

7,083 

.28 

0,071 

.39 

5,312 

.51 

4,722 

.61 

4,250 

.8 

11 

8,570 

.20 

7,340 

.36 

0,428 

.47 

5,714 

.59 

5,142 

.73 

12 

10,192 

.21 

K,73(; 

.33 

7,(548 

.43 

0,796 

..54 

0,120 

.(57 

13 

11,971 

.22 

li>,200 

.31 

8,978 

.39 

7,980 

.49 

7,182 

.61 

14 

13,HH3 

.21 

ii,90;i 

.28 

10,112 

.36 

9,2.55 

.46 

8,330 

.57 

15 

15,937 

.19 

13,0(50 

.20 

11,952 

.34 

10,(524 

.43 

9,5(52 

.53 

ir, 

1H,12H 

.18 

15,  .530 

.21 

13,.1H4 

.32 

12,080 

40 

10,880 

.5 

17 

20,  .500 

.17 

17,. 500 

.23 

15,353 

.30 

13,(547 

..38 

12,282 

•47 

18 

22,932 

.10 

19,(550 

.21 

17/208 

.28 

15.700 

.3(5 

13  752 

.44 

N')TK  'PiiiH  tiililc  shnws  tlw  ^fittest  Weight  that  rv(>r  ou^jht  to 
bf  laiil  iip'iii  a  Oram  I'nr  pcriiiunrnt  Inud;  imd  if  tlier(!  \h\  any  lia- 
bility to  jerks,  (!tc.,  aiuphi  alUiwaiici'  must  be  iiiadi';  also  tlio 
w(;ii;lit  of  the  beam  itself  must  bo  included,  {ike  Tables  of  Cast 
Iron. ) 


STHENGTH   OP   MATORI.VLS.  107 

To  find  the  wehjld  of  a  cast  iron  beam  of  (jlo  .n  ulmensions. 

Rule. — Multiply  the  sectional  area  in  inches  by  the  length  in 
feet,  and  by  3.2;  the  product  equals  the  weight  in  lbs. 

Ex. — Required  the  weight  of  a  uniform  rectangular  beam  of 
cast  iron,  16  feet  in  length,  1 1  inches  in  breadth,  and  1 J  inches  in 
thickness. 

11  X  1-5  X  16  X  3.2  =  844.8  lbs. 

To  determine  the  dimetisioiis  of  a  support  or.  column  to  hear,  without 
sensible  curvature,  a  given  pressure  in  thi  direction  of  its  axis. 

Rule. — Multiply  the  pressure  to  be  supported  in  pounds  by 
the  square  of  the  column's  length  in  feet,  and  divide  the  product 
by  twenty  times  the  tabular  value  of  E;  and  the  quotient  will  be 
equal  to  the  breadth  multiplied  by  the  cube  of  the  least  thickness, 
both  being  exj)ressed  in  inches. 

Note  1. — When  the  pillar  or  support  is  a  square,  its  side  will 
be  the  fourth  root  of  the  quotient. 

Note  2. — If  the  pillar  or  column  he  a  cylinder,  multiply  the 
tabular  value  of  E  by  12,  and  the  fourth  root  of  the  quotient 
equals  the  diameter. 

Ex.  1. — What  should  be  the  least  dimensions  of  an  oak  sup- 
port, to  bear  a  weight  of  2,210  lbs.,  without  sensible  flexure,  its 
breadth  being  3  inches  and  its  length  5  feet? 
Tabular  value  of  E  =  105, 
2240  X  52 


^^^  20X1U5X3  =  V  «.86«  =  2  05  inches. 

Ex.  2. — Required  the  side  of  a  square  piece  of  Riga  fir,  9  feet 

in  length,  to  bear  a  permanent  weight  of  6,000  lbs. 

Tabular  value  of  E  =  96, 

^  6000  X  92       ^    ,-r^        ...  , 

and  -  =  <  v/  253  =  4  inches  nearly. 


Elasticity  of  Torsion,  or  Resistance  of  Bodies  to 

Twisting. 

The  angle  of  flexure  by  torsion  is  as  the  length  and  extensi- 
bility of  the  body  directly,  and  inversely  as  the  diameter;  hence, 
the  length  of  a  bar  or  shaft  being  given,  the  power  and  the  lever- 
age the  power  acts  with  being  known,  and  also  the  number  of 
degrees  of  torsion  that  will  not  aff'ect  the  action  ol  the  machine,  to 
determine  the  diameter  in  cast  iron  with  a  givsn  angle  of  flexure. 

Rule  — Multiply  the  power  in  poiinds  by  the  length  of  the 
shaft  in  feet,  and  by  the  leverage  in  feet;  divide  the  product  by 
fifty-five  times  the  number  of  degrees  in  the  angle  of  torsion; 
and  the  fourth  root  of  the  quotient  equals  the  shaft's  diameter  in 
inches. 


103  STRENGTH   OF   MATERIALS. 

Ex  —Required  the  diameters  for  a  series  of  shafts  33  feet  in 

length,  and  to  transmit  a  power  equal  to  1,245  lbs.,  acting  at  the 

circumference  of  a  wheel  2.}  feet  radius,  so  that  the  twist  of  the 

shafts  on  the  application  of  the  power  may  not  exceed  one  degree. 

1245X35X2.5 


55X1 


:=■<  y  19a  1  =  6.67  inches  in  diameter. 


To  determine  the  side  of  a  square  shaft  to  resist  torsion  loilh  a  given 

Jiexure. 

Rule. — Multiply  the  power  in  pounds  by  the  leverage  it  acts 
•with  in  feet,  and  also  by  the  length  of  the  shaft  in  feet;  divide 
this  product  by  92.5  times  the  angle  of  flexure  in  degrees,  and 
the  square  root  of  the  quotient  equals  the  area  of  the  shaft  in 
inches. 

Ex. — Suppose  the  length  of  a  shaft  to  be  12  feet,  and  to  be 
driven  by  a  power  equal  to  700  lbs  ,  acting  at  one  foot  from  the 
centre  of  the  shaft — required  the  area  of  cross-section,  so  that  it 
may  not  exceed  1  degree  of  flexure. 

700  X  1  X  12 


92.5  X  1 


V-  ^  •!  v/  90.8  =  9.53  inches. 


Relative  Strength  of  Bodies  to  resist  Torsion,  Lead 

being  1. 


Tin 1.4 

Copper 4.3 

Yellow  Brass   . .  4.6 


Gun-Metal 5.0 

Cast  Iron 9.0 

Swedish  Iron  . .  .9.5 


English  Iron.  . .  10. 1 
Blistered  Steel  .16.6 
Shear  Steel..  ..17.0 


Sftr  of  Iron. — The  average  breaking  weight  of  a  bar  of 
■wrought  iron,  1  inch  scpiare,  is  25  tons;  its  elasticity  is  destroyed, 
however,  by  about  two-tifths  of  that  weight,  or  10  tons.  It  is 
extended,  within  the  Uiuits  of  its  elasticity,  .t)  lOO'Jfi,  or  one  ten- 
thousandtli  part  of  an  inch  for  every  ton  of  strain  jxTsijuarc  inch 
of  sectional  area.  Ilcaice,  the  greatest  constant  load  shouhl  never 
exceed  one-tifth  of  its  breaking  weight,  or  Stuns  for  every  square 
inch  of  sectional  area. 

The  lateral  strength  of  wrought  iron,  as  compared  with  cast 
iron,  is  as  14  to  9.  Mr.  Barlow  finds  that  wrouglit  iron  bars,  3 
inches  deep,  1-^  indies  thick,  and  ^3  inches  between  the  sup- 
ports, will  carry  4^  tons. 

lir h I ffrx. -The  greatest  extraneous  load  on  a  square  foot  in 
about  IJO  pounds. 

Floors.     Till!  least  load  on  a  square  foot  is  about  160  pounds. 

Itoofs.     Covcn-d  with  slate,  on  a  square  foot.  51  i  pounds. 

Jicti ins.  When  a  beam  is  sii]qi(irt<'d  in  the  miildlc  and  loaded 
at  each  <iid,  it  will  bear  tlu;  saiin'  wtiglit  as  when  Hniq><irt<'d  at 
both  ends  ami  loaded  in  the  middle;  that  is,  each  end  will  bear 
half  the  weight. 


STRENGTH   OP   MATERIALS.  109 

Cast  iron  beams  should  not  be  loaded  to  more  than  one-fifth 
of  their  ultimate  strength. 

The  strength  of  similar  beams  varies  inversely  as  their  lengths; 
that  is,  if  a  beam  10  feet  long  will  support  1,0U0  pounds,  a  simi- 
lar beam  20  feet  long  would  support  only  500  pounds. 

A  beam  su^jported  at  one  end  will  sustain  only  one-fourth  part 
the  weight  which  it  would  if  supported  at  both  ends. 

When  a  beam  is  fixed  at  both  ends  and  loaded  in  the  middle 
it  will  bear  one-half  more  than  it  will  when  loose  at  both  ends. 
When  the  beam  is  loaded  uniformly  throughout  it  will  bear 
double.  When  the  beam  is  fixed  at  both  ends  and  loaded  uni- 
formly throughout  it  will  bear  trij^le  the  weight. 

In  any  beam  standing  obliquely,  or  in  a  slojnng  direction,  its 
strength  or  strain  will  be  equal  to  that  of  a  beam  of  the  same 
breadth,  thickness,  and  material,  but  only  of  the  length  of  the 
horizontal  distance  between  the  points  of  support. 

In  the  construction  of  beams  it  is  necessarj'  that  their  form 
should  be  such  that  they  will  be  equally  strong  throughout.  If 
a  beam  be  fixed  at  one  end  and  loaded  at  the  other,  and  the 
breadth  uniform  throughout  its  length,  then,  that  the  beam  may 
be  equally  strong  throughout,  its  form  must  be  that  of  a  parabola. 
This  form  is  generally  used  in  the  beams  of  steam-engines. 

When  a  beam  is  regularly  diminished  toward  the  points  that 
are  least  strained,  so  that  all  the  sections  are  similar  figures, 
whether  it  be  supported  at  each  end  and  loaded  in  the  middle, 
or  supported  in  the  middle  and  loaded  at  each  end,  the  outline 
should  be  a  cubic  parabola. 

When  a  beam  is  supported  at  both  ends  and  is  of  the  same 
breadth  throughout,  then,  if  the  load  should  be  uniformly  dis- 
tributed throughout  the  length  of  the  beam,  the  line  bounding 
the  compressed  side  should  be  a  semi-ellipse. 

The  same  form  should  be  made  use  of  for  the  rails  of  a  wagon- 
way,  where  they  have  to  resist  the  pressure  of  a  load  rolling  over 
them. 

Similar  plates  of  the  same  thickness,  either  supported  at  the 
ends  or  all  round,  will  carry  the  same  weight  either  uniformly 
distributed  or  laid  on  similar  points,  whatever  be  their  extent. 

The  lateral  strength  of  any  beam  or  bar  of  wood,  stone,  metal, 
&c.,  is  in  proportion  to  its  breadth  multiplied  by  the  square  of  its 
depth.  In  square  beams  the  lateral  strengths  are  in  proportion 
to  the  cubes  of  the  sides,  and  in  general  of  like-sided  beams  as 
the  cubes  of  the  similar  sides  of  the  section. 

The  lateral  strength  of  any  beam  or  bar,  one  end  being  fixed 
in  the  wall  and  the  other  projecting,  is  inversely  as  the  distance 
of  the  weight  from  the  section  acted  upon;  and  the  strain  upon 
any  section  is  directly  as  the  distance  of  the  weight  from  that 
section. 

The  absolute  strength  of  ropes  or  bars  pulled  lengthwise,  is  in 
proportion  to  the  squares  of  their  diameters.  All  cylindrical 
or  prismatic  rods  are  equally  strong  in  every  part,  if  they  are 
equally  thick,  but  if  not  they  will  break  where  the  thickness  is 
least. 


110  STRENGTH   OP   MATERIALS. 

The  strength  of  a  tube  or  hollow  cylinder  is  to  the  strength  of 
a  solid  one,  as  the  diflference  between  the  fouith  powers  of  the  ex- 
terior and  interior  diameters  of  the  tube,  divided  by  the  exterior 
diameter,  is  to  the  cube  of  the  diameter  of  a  solid  cylinder — the 
quantity  of  matter  in  each  being  the  same.  Hence,  from  this  it 
will  be  found  that  a  hollow  cylinder  is  one-half  stronger  than  a 
solid  one  having  the  same  weight  of  material. 

The  strength  of  a  column  to  resist  being  crushed  is  directly  as 
the  square  of  the  diameter,  provided  it  is  not  so  long  as  to  have 
a  chance  of  bending.  This  is  true  in  metals  or  stone,  but  in  tim- 
ber the  proportion  is  rather  greater  than  the  S(j[uare. 


Models  proportioned  to  Macliines. 

The  relation  of  models  to  machines  as  to  strength,  deserves  the 
particular  attention  of  the  mechanic.  A  model  may  be  perfectly 
proportioned  in  all  its  parts  as  a  model,  yet  the  machine,  if  con- 
structed in  the  same  proportion,  will  not  be  sufficiently  strong 
in  every  part;  hence,  particular  attention  should  be  paid  to  the 
kind  of  strain  the  diS'ereut  j)arts  are  exposed  to;  and  from  the 
statements  which  follow,  the  proper  dimensions  of  the  structure 
may  be  determined. 

If  the  strain  to  draw  asunder  in  the  model  be  1,  and  if  the 
structure  is  8  times  larger  than  the  model,  then  the  stress  in  the 
structure  will  be  H-'  equals  512.  If  the  structure  is  G  times  as  largo 
as  the  model,  then  the  stress  on  the  structure  will  be  G-'  equals 
210,  and  so  on;  therefore  the  structure  will  be  much  less  firm 
than  the  model;  and  this  tlie  more,  as  the  structure  is  cube 
times  greater  than  the  model.  If  we  wish  to  determine  the  greatest 
size  we  can  make  a  machine  of  which  we  have  a  model,  we  have, 

The  greatest  weight  which  the  beam  of  the  model  can  bear,  di- 
vided by  the  weight  which  it  actually  sustains,  equals  a  quotient 
which,  when  multiplied  by  the  size  of  the  beam  in  the  model, 
will  give  the  greatest  possible  size  of  the  same  beam  in  the  struc- 
ture. 

Example. — If  a  beam  in  the  model  be  7  inches  long,  and  bear  a 
weight  of  4  lbs.,  but  is  ca)iable  of  bearing  a  weight  of  20  lbs.,  what 
is  tiie  greatest  length  which  we  can  malce  the  corresponding  beam 
in  the  structure?     Here 

20  -;-  4  =  0. 5 ;  the-elbre,  C.  3  X  7  ^  45. 5  inches. 

The  strength  to  resist  crushing  increases  from  a  model  to  a 
structure  in  proportion  to  their  size,  but,  as  above,  the  strain  in- 
creases a.s  the  cubes;  wherefore,  in  this  case,  also,  the  model  will 
be  8trong(!r  than  the  machine,  and  the  greatest  size  of  the  struc- 
ture will  b(!  found  by  enii)loying  tlie  stjuare  root  of  the  quotient 
in  th(!  last  ruli',  iustea<l  of  tlie  (juotient  itself;  tlius, 

If  the  greatest  weiglit  wliich  tlie  coluiiiu  in  a  modi^l  can  bear  is 
3  cwt.,  and  if  it  actually  bears  2S  lbs.,  then,  if  tho  column  bo  Id 
inches  high,  we  have 

\  28  )  "^  ^-  '^^''^  '        wherefore  3. 404  X  18  =  62. 352 
inches,  the  length  of  tho  column  in  tho  structure. 


J 


STRENGTH   OF   MATERIALS.  Ill 

List  of  Metals,  akrakged  accokding  to  their  strength. — Steel, 
■wrought  iron,  cast  iron,  platinum,  silver,  copper,  brass,  gold, 
tin,  bismuth,  zinc,  antimony,  lead. 

According  to  Tredgold's  and  Duleaii's  experiments,  a  piece  of 
the  best  bar-iron  I  square  inch  across  the  end  -would  bear  a 
■weight  of  about  77,373  lbs.  while  a  similar  piece  of  cast  iron 
■would  be  torn  asunder  by  a  weight  of  from  16,243  to  19,464  lbs. 
Thin  iron  -wires,  arranged  parallel  to  each  other,  and  presenting 
a  surface  at  their  extremity  of  1  square  inch,  ■will  carry  a  mean 
weight  of  126,340  lbs. 

List  of  Woods,  arranged  according  to  their  strength.  —  Oak, 
alder,  lime,  box,  pine  ("yJv  ),  ash,  elm,  yellow  pine,  fir 

A  piece  of  well-dried  pine  wood,  presenting  a  section  of  1 
square  inch,  is  able,  according  to  Eytelwein,  to  support  a  weight 
of  from  1),646  lbs.  to  20,408  lb?.,  whilst  a  similar  piece  of  oak 
■will  carry  as  much  as  25,f5>,'0  lbs 

Hempen  cords,  twisted,  will  support  the  following  weights  to 
the  square  inch  of  their  section. 

\  inch  to  1  inch  thick,  8,746  lbs. ;  1  to  3  inches  thick,  6,800  lbs. ; 
3  to  5  inches  thick,  5,345  lbs. ;  5  to  7  inches  thick,  4,860  lbs. 

Tredgold  gives  the  following  rule  for  finding  the  weight  in 
pounds  which  a  hempen  rope  will  be  capable  of  supporting  : 
Multiply  the  square  of  the  circumference  in  inches  by  200,  and 
the  product  -will  be  the  quantity  sought. 

In  the  practical  application  of  these  measures  of  absolute 
strength,  that  of  metals  should  be  reckoned  at  one-half,  and  that 
of  woods  and  cords  at  one-third  of  their  estimated  value. 

In  a  parallelopipedon  of  uniform  thickness,  supported  on  two 
points  and  loaded  in  the  middle,  the  lateral  strmqth  is  directly  as 
the  product  of  the  breadth  ii^to  the  square  of  the  depth,  and  im  ersely_  as 
the  length.  Let  W  represent  the  lateral  strength  of  any  material, 
estimated  by  the  weight,  h  the  breadth,  and  (/  the  depth  of  its 
end,  and  I  the  distance  between  the  points  of  support ;  then 

If  the  parallelopipedon  be  fastened  only  at  one  end  in  a  hori- 
zontal position,  and  the  load  be  applied  at  the  opposite  end, 
W=/(i-5-:-4Z. 

It  is  to  be  observed  that  the  three  dimensions,  b,  d,  and  I,  are 
to  be  taken  in  the  same  measure,  und  that  h  be  so  great  that  no 
lateral  curvature  arise  from  the  weight ;  /  in  each  formula  rep- 
resents the  1  iteral  strength,  which  varies  in  differe-ut  materials, 
and  which  must  be  learnt  experimentallj'. 

A  beam  having  a  rectangular  end,  whose  breadth  is  two  or  three 
times  greater  than  the  breadth  of  another  beam,  has  a  po-R-er  of 
suspension  respectively  two  or  three  times  greater  than  it;  if  the 
end  be  two  or  three  times  deeper  than  the  end  of  the  other,  the 
suspension  power  of  that  which  has  the  greater  depth  exceeds 
the  suspension  power  of  the  other  four  or  nine  times  ;  if  its 
length  be  two  or  three  times  greater  than  the  length  of  another 
beam,  its  power  of  suspension  will  be  A  or  ^  respectively  that  of 
the  other  ;  provided  that  in  each  case'the  mode  of  suspension, 
the  position  of  the  weight,  and  other  circumstances  be  similar. 


112 


STRENGTH   OF    MATERIALS. 


Hence  it  follows  that  a  beam,  one  of  whose  sides  tapers,  has  a 
greater  power  of  suspension  if  placed  on  a  slant  than  on  the 
bi'oad  side,  and  that  the  powers  of  suspension  in  both  cases  are 
in  the  ratio  of  their  sides;  so,  for  instance,  a  beam,  one  of  whose 
sides  is  double  the  width  of  the  other,  will  carry  twice  as  much 
if  placed  on  the  narrow  side,  as  it  wovild  if  laid  on  the  wide  one. 
In  a  piece  of  round  timber  (a  cylinder)  the  power  of  suspen- 
sion is  in  proportion  to  the  diameters  cubed,  anil  inversely  as  the 
length  ;  thus  a  beam  %vith  a  diameter  two  or  three  times  longer 
tl:an  that  of  another,  will  carry  a  weight  8  or  27  times  heavier 
respectively  than  that  whose  diameter  is  unity,  the  mode  of 
faste  dng  and  loading  it  being  similar  in  both  cases. 

The  lateral  strength  of  square  timber  is  to  that  of  a  tree 
whence  it  is  hewn  as  10  :  17  nearly. 

A  considerable  advantage  is  frequently  secured  by  using 
hollow  cylinders  instead  of  solid  ones,  which,  with  an  equal  ex- 
penditure of  materials,  have  far  greater  strength,  proviiled  only 
that  the  solid  part  of  the  cylinder  be  of  a  sufficient  thickness, 
and  that  the  workmanship  be  good;  esi:)ecially  that  in  cast  metal 
beams  the  thickness  be  uniform  and  the  metal  free  from  flaws. 
According  to  Eytelwein,  such  hollow  cylinders  are  to  solid  ones 
of  equal  weight  of  metal  as  1.212  : 1,  when  the  inner  semi-diame- 
ter is  to  the  outer  as  1  :  2  ;  according  to  Tredgoldas  17  :  10,  when 
the  two  semi-diameters  are  to  each  other  as  15  :  25;  and  as  2  : 1, 
when  they  are  to  each  other  as  7  :  10. 

A  method  of  increasing  the  suspensive  power  of  timber  sup- 
ported at  both  ends,  is,  to  saw  down  from  ^  to  },  of  its  depth, 
and  forcibly  drive  in  a  wedge  of  metal  or  hard  wood,  until  the 
timber  is  slightly  raised  at  the  middle  out  of  the  horizontid  line. 
By  experiment  it  was  found  that  the  suspensive  jiower  of  a  beam 
thus  cut  ^  of  its  depth  was  increased  l-19th,  when  cut  J  it  was 
incn^ased  l-29th,  and  when  cut  i|  through  it  was  increased'l-87th. 

The  force  required  to  crush  a  body  increases  as  the  section  of 
the  body  increases  ;  and  this  quantity  being  constant,  the  re- 
sistance of  the  body  diminishes  as  the  height  increases. 

According  to  Eytelwein's  experiments,  tlie  strength  of  columns 
or  timbers  of  rectangular  form  in  resisting  compression  is,  as 

1.  The  cube  of  their  thickness  (the  lesser  dimension  of  their 
section).  2.  As  the  breadth  (the  greater  dimension  of  their 
section).     3.  Inversely  as  the  sipiare  of  their  length. 


Cohesive  Power  of  Bars  of  Metal  one  inch  square, 

in  Tons. 


Iron  Swedish  bur 29.20 

"    liuRsiiin  bur, 2r).70 

'•     Euglish  bar 25.00 

Steel  cast r>'.}.'X] 

"     blittti-red,   r,'.).r.i 

"     sheer,    Cr,.97 


Copper,  wrought, 1.').08 

(Jnn-mctal 16.23 

Copper,  cast, 8.51 

I5ra.ss,  cast,  yellow 8.01 

Iron,  ciist, 7.H7 

Tin,  cast, 2.11 


STRENGTH   OF   MATERIALS. 


113 


Relative  Strength  of  Cast  and  Malleable  Iron. 

It  has  been  found,  in  the  course  of  the  experiments  made  by 
Mr.  Hodgkinson  and  Mr.  Fairbairn,  that  the  average  strain  that 
cast  iron  will  bear  in  the  way  of  tension,  before  breaking,  is 
about  seven  tons  and  a  half  per  square  inch  ;  the  weakest,  in 
the  course  of  16  trials  on  various  descriptions,  bearing  6  tons, 
and  the  strongest  9|  tons.  The  experiments  of  Telford  and 
Brown  show  that  malleable  iron  will  bear  on  an  average  'Al  tons; 
the  weakest  bearing  24,  and  the  strongest  29  tons.  On  approach- 
ing the  breaking  point,  cast  iron  may  snap  in  an  instant,  with- 
out any  previous  symptom,  while  wrought  iron  begins  to  stretch 
with  half  its  breaking  weight,  and  so  continues  to  stretch  till  it 
breaks.  The  experiments  of  Hodgkinson  and  Fairbairn  show 
also  that  cast  iron  is  capable  of  sustaining  compression  to  the  ex- 
tent of  nearly  50  tons  on  the  square  inch  ;  the  weakest  bearing 
30 J  tons,  ard  the  strongest  60  tons.  In  this  respect,  malleable 
iron  is  much  inferior  to  cast  iron.  With  12  tons  on  the  square 
inch  it  yields,  contracts  in  length,  and  expands  laterally  ; 
though  it' will  bear  27  tons,  or  more,  without  actual  fracture. 

Eennie  states  that  cast  iron  may  be  criished  with  a  weight  of 
93,000  lbs.     and  brick  with  one  of  562  lbs.,  on  the  square  inch. 


Strength  of  Beams. 

SOLID,  EECTANGULAU,  AND  BOUND  :    TO  FIND  THEIR  STKENGTH. 

t^quare  and,  Eedangular. 

(Depth  ins.  )2X  Thickness  ins.       m  i  .  -vt  t.      i-       _i    x 

^ — i- ^         \ — 7 X  Tab  r  No.  =  Breaking  wt.,  tons. 

Length,  ft. 


Round. 


(Diameter  ins.l^ 
Length  in  ft. 


X  Tabular  No.  =  Breaking  weight,  tons. 
Hollow. 


(Outsidedia.ins.)3-(Insidedia.ins.)  ^  ^^^^^^^^  ^.^    ^^^^^^^ 
Length,  ft. 

ing  weight,  tons. 


Thicknees  not  exceeding  j 


1  in.  for  iron 
3  in.  for  wood 


2  in.  for  iron  3  in.  for  iron 
6  in. for  wood  12  in.,  wood 


Round. 


Cast  and  wrought  iron 

Teak  and  greenheart I 

Fir  and  English  oak I 


.8 

.28 

.14 


114 


STRENGTH   OF   MATERIALS. 

Square  and  Rectangular. 


Cast  and  wrought  iron 

Teak  and  greeuheart ....... 

Pitch    pine     and    Canadian 

oak 

Fir,   red  pine,  and  English 

oak 


.1 

.36 

.85 
.32 

.7 
.26 

.25 

.22 

.18 

.18 

.16 

.13 

To  FIND  THE  BkEAKING  WeIGHT  IN  PoUNDS  USE  THE  TaBULAB 
NUMBEK    BELOW. 


m  •  1  1  T       1  1  in.  for  iron 

Thickness  not  exceeding  \  Uiu.foj-wood 


2  in.  for  iron 
6  in. for  wood 


3  in.  for  iron 
12  in.,  wood 


Square  and  Rectangular. 


Iron 

Teak 

Fir  and  oak . 


2,240 

1,900 

1,570 

800 

710 

570 

100 

355 

285 

Round. 


Iron 

Teak 

Fir  and  oak 


Though  wronght  and  cast  iron  are  represented  in  these  rules 
as  of  equal  strength,  it  should  be  observed  that  wliiUi  a  cast  iron 
Vmr  1  inch  X  1  inch  X  1  loot  0  inch  h)ng,  of  average  (juality,  will 
l)reiik  with  one  ton,  a  siinil.ir  Inir  of  wrouglit  iron  only  loses  its 
elasticity,  and  deflects  l-ldth  of  an  inch,  yet  as  it  can  only  carry 
a  further  wiiglit  by  destroying  its  shape  and  increasing  the  de- 
flection, it  is  best  to  calculate  on  the  above  basis: 

DldrctH 

(  1-16  with  Iton. 

L'-^     1-H      " 


A  wrought  iron  ])ar  1  inX  1  in  X  1  ft.  Gin.  long 


l2U2 


2\  " 


The  above  rule  gives  the  weight  that  will  break  the  beam  if  put 
on  the  middle.  If  tln^  weight  is  laid  ((lually  all  over,  it  would 
ri'(iuire  dou])l(!  the  weiglit  to  lireak  it. 

A  biiini  should  not  be  loaded  with  more  than  1-3  of  tho  break- 
ing weight  in  any  (-ase,  and  as  a  general  rule  not  with  more  than 
1-4.  for  the  ])ur|)oses  of  machinery  not  with  more  than  1-6  to  1-10, 
depending  on  circumstuuceB. 


STRENGTH   OF   MATERIALS. 

To  FIND  THE  PeoPER  SizE  FOB  ANY  GIVEN  PURPOSE. 

Hectangidar. 
Weight  X  Length,  ft 


115 


Tabular  No. 


X  3  or  4  or  6,  &c  ,  according  to  circumstan- 
ces =  B  D^  ins. 
Round. 


■V 


5    /  Weight  X  Length,  ft. 


Tabular  No. 


X  3  or  4  or  6,  «tc.,  according  to  circum- 


stances =^  diiim.  ins. 


Solid  Columns. 

Fail  by  crushing  with  length  under 5  diameters 

Principally  by  crushing  from 5  to  15  " 

Partly  by  crushing,  partly  by  bending,  from.  15  to  25  " 

Altogether  by  bending  above   25  " 

Cast  iron  of  average  quality  is  crushed  with  .  .49  tons  per  sq.  in. 
Wr'ght  iron  of  average  quality  is  crushed  with..  16      "         " 
Wrought  iron  is  permanently  injured  with. .  .12      "         " 

Oak  wrought  is  crushed  with 4      "        " 

Deal  wrought  is  crushed  with 2      "         " 

The  comparative  strength  of  dififerent  columns,  of  diflferent 
lengths,  will  be  seen  very  clearly  from  the  following  table  derived 
from  experiments  by  Mr.  Hodgkinson  : 


Wrought  Iron  Bars. 

Proportion  of  Length 
to  Thickness. 

Gave  way  with 

Square. 

Length. 

ins. 

ft.  ins. 

1   X   1 

7.i 

7^tol 

21.7  tons  per  sq.  inch. 

(( 

1     3 

15    tol 

15.4 

(( 

2     6 

30    to  1 

11.3 

(( 

5    0 

60    tol 

7.5 

it 

7     6 

90    tol 

4.3 

^  X   ^ 

5    0 

120    tol 

2.5 

(( 

7     6 

180    to  1 

1. 

To  FIND  THE  Strength  of  any  Wrought  Iron  Column  with 

Square  Ends. 

Area  of  column  sq.  inches  X  tons  per  inch  corresponding  to  pro- 
portion of  length,  as  per  table  above  =  Breaking  weight,  tons. 

If  the  ends  are  rounded,  divide  the  final  result  by  3  to  find  the 
breaking  weight. 

In  columns  of  oblong  section,  the  narrowest  side  must  always 
be  taken  in  calculating  the  proportion  of  height  to  width. 


116 


STRENGTH   OF   MATERIALS. 


To  FIND  THE  Strength  of  Round  Columns  exceeding  25  diametebs 

IN  LENGTH — Mb.   HoDGKINSON's  KuLE. 

■^ r-^- — ^ X  Tabular  No.  =  Breaking  weicht,  tons. 

(Length,  ft.)'-'  &         fa     > 


"Wrought  iron 

Cast  iron . 

Dantzic  oak. , 
Ked  deal 


Rounded  or  Movable 

Square  Ends. 

Ends. 

77 

26 

U 

15 

4.5 

L7 

3.3 

L2 

A  column  should  not  bo  loaded  Avith  more  than  1-3  of  the 
breaking  weight  in  any  case,  and  as  a  general  rule,  not  with  more 
than  1-4;  for  purposes  of  machinery  not  with  more  than  1-6  to 
1-10,  according  to  circumstances. 


Tables  of  Powers  for  the  Diameters  and  Lengths 

of  Columns. 


Diameter. 

3.G  Power. 

Diameter. 

3.6  Power. 

1  in. 

1. 

7  in. 

1,102.4 

2  23 

k 

1,251. 

]  ■ 

4.3 

i 

1,413.3 

7.5 

i 

1,590.3 

2 

12.1 

8 

1,782.9 

\ 

18.5 

i 

1,991.7 

27. 

t 

4 

2,217.7 

i 

38.16 

2,461.7 

3 

52.2 

9 

2, 72}.  4 

i 

6i).63 

\ 

3,006.85 

90.9 

3,309.8 

116.55 

1 

3,634.3 

4 

147. 

10 

3,981.07 

\ 

182  9 

i 

4,351.2 

I 

224.68 

1 

4.741.5 

i 

272.96 

t 

1 

5,165. 

5 

328.3 

11 

5,610.7 

r 

391.36 

\ 

6,083.4 

1 

462.71 

6,584.3 

1 

543.01 

7,114.4 

6 

632.91 

rj' 

7,674.5 

1           : 

733. 1 1 

1 ' 

844.28 

967.15 

Length. 

1-7  Power. 

1 

1. 

2 

3.25 

3 

6.47 

4 

10.556 

5 

15.426 

6 

2L031 

7 

27.332 

8 

34.297 

9 

41.9 

10 

50.119 

11 

58.934 

12 

68.329 

13 

78.289 

14 

88.8 

15 

99.85 

16 

111.43 

17 

123.53 

18 

136.13 

19 

149.24 

20 

162.84 

21 

176.92 

22 

191.48 

23 

206.51 

21 

222. 

STRENGTH   OF  MATERIALS. 


117 


Hollow  Columns, 

Hollow  columns  fail  principally  by  crushing,  provided  the 
length  does  not  exceed  25  diameters  ;  indeed  the  length  does  not 
appear  to  aflfect  the  strength  much  till  it  exceeds  50  diameters. 

The  comparative  strength  of  different  forms  and  of  different 
thicknesses  will  appear  so  distinctly  from  the  experiments  below, 
made  by  Mr.  Hodgkinson,  that  no  difficulty  will  be  found  in 
ascertaining  the  strength  due  to  any  size  or  form  of  column  that 
may  be  required. 

Square  Columns  of  Plate  Iron  eiyeted. 


Columns  10  feet  0  inches  long. 


Size. 

Thick- 

Proportion   of 

uess. 

Thickness  to  Width. 

4  in.  X  4  in. 

.03 

iS 

(< 

.06 

;^g 

(( 

.1 

io 

<( 

.2 

h 

8  in.  X  8  in. 

.06 

I33 

t< 

.14 

-h 

(t 

.22 

/e 

(( 

.25 

vh 

Proportion 
of  Length 
to  Width. 


30  to  1 


15tol 


Break'g  w'ght 

Tons  per  eq. 

m.  of  section. 


4.9 

8.6 
10. 
12. 

6. 

9. 

11.5 
12. 


Column  SJeet  0  inches  long. 

18  X  18           .5        ^\  practically.      5.4  to  1 

13.6 

Column  10  feet  0  inches  long,  with  cells. 

Sin.  X  8  in.      .06       J- of  width  of  cells.      15tol 

8.6 

To  find  the  Strength  of  any  Hollow  Wrought  Iron  Column. 

Q  •        s/  /'tons  per  inch,  corresponding  to  the  pro-\ 

&ec.  area,  sq.  ins.  X  V  portions  of  length  and  thickness  to  width  j 

=  Breaking  weight,  tons. 
Columns  of  Oblong  Section. 

The  strength  of  these  may  be  ascertained  by  the  same  rule  as 
that  of  square  columns.  The  smallest  width  being  taken  in  cal- 
culating the  proportion  of  height  to  width,  while  the  longest  side 
must  be  taken  into  consideration  in  calculating  the  proportion 
of  thickness  to  width. 


118 


STiiENGTH   OF   MATERIALS. 
Column  10  feet  0  incJies  long. 


Size. 

Thick- 
ness. 

Proportion  of 

Thickness  to 

greatest  Width. 

Proportion  of 

Length  to  least 

■Width. 

Breaking  wt. 

tons  p»r 
sq.  in.  of  seo. 

8  in  X  4  in. 

.06 

3;f5 

30  to  1 

6.78 

Bound  Columns  of  Piate  Ibon  Riveted. 


Columns  10  feet  0  inches  in  length. 


Dia- 

Thick- 

meter. 

ness. 

1 

n. 

.1 

2 

.1 

'if, 

.1 

n 

.24 

n 

.21 

3 

•15 

4 

.15 

6 

.1 

6 

.13 

Proportion 
of   thick- 
ness to 
Diameter. 


ao 

1 

la 

1 

is 

^^ 

1 


D-       _i-       Breaking 
Proportion  |  Weight 

of  length  to  Tons  per 


Diameter. 


80  to 
60  to 
48  to 
48  to 
48  to 
40  to 
30  to 
20  to 
20  to 


sq.   inch 


6.5 
10.35 
13.3 
9.6 
9.9 
12.36 
12.34 
15. 
18.6 


Same  Columns 
Reduced  in  Length. 

Breaking  Weights. 
Tons  pi  r  square  inch. 


5  ft.  0  in.  long 


'3.9 
.4.8 
15.6 
15.6 
13. 
13. 
13. 
17. 


!  ft.  6  in.  long 


5.8 
16.5 
16.3 
16. 
17. 
16.5 

18.6 


It  would  Rcem  from  this  that  a  thickness  of  1-48,  or  \  inch 
in  thickness  for  every  foot  in  iliivmeter,  is  a  good  proportion  for 
this  kind  of  column. 

It  will  be  seen  from  these  cxporiments,  that  it  is  the  propor- 
tion of  thickness  to  the  width  of  cell  which  regulates  the  strength 
•vitliin  certain  limits  of  height. 

And  that  a  tliickncss  of  1  :iO  or  J  inch  for  every  4  inches  in 
width  will  give  the  highest  result  practicable  for  square  columns. 


Crano. 

Tlin  strains  on  tlm  i)rinci])iil  j)iirts  can  bo  ascertained  with 
(^.-•yit  f'UKi'  in  the  f<jllowing  manner— the  strength  being  propor- 
tioned accordingly. 


To  FIND  THE  Strain  on  the  Post. 
Weight  suspended,  tons  X  Projection,  feet 


j  Strain  on  top 
j      jiost,  tons. 


of 


Ilfright  of  ])f)st  abnvi'  ground,  feet 

The   i)ost  run   then   b"  (;:i'i:iiliit<'d   as  a  beam,  twice  as  long  as 

ihia  height  from  ypnin  I,  with  twico  the  weight  on  the  middle. 


STRENGTH   OP   MATERIALS.  119 

Cold.  Water  Piimp. 

Usually  \  of  cylinder  diameter  when  the  stroke  is  ^  that  of  piston. 


1  "  I'  I 


3 


To   FIND    THE   PROPER   SIZE,   UNDER  ANT  CIECITMSTANCES,   CAPABLE  OF 
SUPPLYING  TWICE  THE  QUANTITY  OBDINABILT  USED  FOR  INJECTION. 

Cub   ft.  water  per  hour  used  in  form  of  steam J  Area  of  pump 

Stroke  of  pump,  ft.  X  strokes  per  minute  I    ^^  square  ft. 


Tensile  Strength. 

Tensile  Strength  is  the  resistance  of  the  fibres  or  particles 
of  a  body  to  separation.  It  is  therefore  proportional  to  their 
number,  or  to  the  area  of  its  transverse  section. 

The  fibres  of  wood  are  strongest  near  the  centre  of  the  trunk 
or  limb  of  a  tree. 

Cast  Iron. — Experiments  on  cast  iron  bars  give  a  tensile 
strength  of  from  4,UU0  lbs.  to  5,0i'0  lbs.  per  square  inch  of  its 
section,  as  just  suflicient  to  balance  the  elasticity  of  the  metal ; 
and  as  a  bar  of  it  is  extended  the  5,50Uth  part  of  its  length  for 
every  ton  of  direct  strain  per  square  inch  of  its  section,  it  is  de- 
duced that  its  elasticity  is  fully  excited  when  it  is  extended  less 
than  the  3,OU0th  part  of  its  length,  and  the  extension  of  it  at  its 
limit  of  elasticity  is  estimated  at  the  1,200th  part  of  its  length. 

The  mean  tensile  strength,  then,  of  cast  iron  being  from  fc.OOO 
to  20,000  lbs.,  the  value  of  it,  when  subjected  to  a  tensile  strain, 
may  be  safely  estimated  at  from  i  to  ^  of  this,  or  of  its  breaking 
strain. 

A  bar  of  cast  iron  will  contract  or  expand  .000006173,  or  the 
162,000th  of  its  length  for  each  degree  of  heat;  and  assuming  the 
extreme  range  of  the  temperature  in  this  country  140°  (  —  2U°  -|- 
120°),  it  will  contract  or  expand  with  this  change  .0008642,  or  the 
1,157th  part  of  its  length.  It  shrinks  in  cooling  from  .0104  to 
.0118th  of  its  length. 

It  follows,  then,  that  as  2,240  lbs.  will  extend  a  bar  the  5,500th 
part  of  its  length,  the  contraction  or  extension  for  the  1,157th 
part  will  be  equivalent  to  a  force  of  10,648  lbs.  (4J  tons)  per 
square  inch  of  section. 

Cast  iron  (Greenwood)  at  three  successive  me'.tings  gave  tena- 
cities of  21,300,  30,100,  and  35,700  lbs. 

Cast  iron  at  2.5  tons  per  square  inch  will  extend  the  same  as 
wrought  iron  at  5.6  tons. 

The  mean  tensile  strength  of  four  kinds  of  English  cast  iron, 
as  determined  by  the  Commissioners  on  the  Application  of  Iron 
to  Kailway  Structures,  was  15,711  lbs.  per  square  inch  (7.014  tons); 
and  the  mean  ultimate  extension  was,  for  lengths  of  10  feet, 


120  STRENGTH   OP  MATERIALS. 

.1997  inch,  being  the  600th  part  of  its  length;  and  this  weight 
woukl  compress  a  bar  the  775th  part  of  its  length. 

Tensile  strength  of  the  strongest  piece  of  cast  iron  ever  tested 
—45,970  lbs.  This  was  a  mixture  of  grades  1,  2,  and  3  of  Green- 
wood iron,  and  at  the  third  fusion. 

WroiKjht  Iron.  —Experiments  on  wrought  iron  bars  give  a 
tensile  strength  of  from  18,000  lbs.  to  22,400  lbs.  i)er  square  inch 
of  its  section,  as  just  sufficient  to  balance  the  elasticity  of  the 
metal;  and  as  a  bar  of  it  is  extended  the  10,000  part  of  its  length 
for  every  ton  of  direct  strain  per  square  inch  of  its  section,  it  is 
deduced  that  its  elasticity  is  fully  excited  when  it  is  extended 
the  1,000th  part  of  its  length,  and  the  extension  of  it  at  its  limit 
of  elasticity  is  estimated  at  the  1,520th  part  of  its  length. 

The  mean  tensile  strength  of  wrought  iron  being  from  55,0  0 
to  G5,000  lbs.,  the  value  of  it,  when  subjected  to  a  tensile  strain, 
may  be  safely  estimated  at  from  J  to  ^  of  this,  or  of  its  breaking 
Btrain. 

A  bar  of  wroiight  iron  will  oxj)and  or  contract  .000000614,  or 
the  151,200th  part  of  its  hingth  for  each  degree  of  heat;  and  as- 
suming, as  before  stated  for  cast  iron,  that  the  extreme  range  of 
temperat'.  re  in  the  air  in  this  country  is  140'^,  it  will  contract  or 
expand  with  this  change  .000926,  or  the  l,('80th  of  its  length, 
which  is  equivalent  to  a  force  of  20,740  lbs.  (9|  tons)  per  square 
inch  of  section. 

Experiments  upon  wrought  iron,  to  determine  the  results  from 
rejieatcd  heating  and  laminating,  furnished  the  following: 

From  one  to  six  reheatings  and  rollings,  the  tensile  stress  in- 
creased from  43,904  lbs.  to  61,824  lbs.,  jind  from  six  to  twelve  it 
was  reduced  to  43,904  again. 

The  tensile  force  of  metals  varies  with  their  temperature,  gen- 
erally decreasing  as  the  temperature  is  increased.  In  silver  the 
tenacity  decreases  more  rapidly  than  the  temi)erature;  in  copper, 
gold,  and  platinum  it  decreases  less  rapidly  than  the  tempera- 
ture. 

In  iron  the  tensile  strength  at  different  temperatures  is  as  fol- 
lows: 60^  1;  114°,  1.14;  212^  1.2;  250°,  1.32;  270",  1.35;  325",  1.41; 
435",  1.4. 

StirUtm^s  Mi.iuil  or  Tonnhcncd  Iron.— By  tlio  mix- 
ture of  a  jtortion  of  iiiulleul)lt'  iron  with  crast  iron,  carefully  fuscrl 
in  a  cru(!ible,  a  tcnsil(^  strain  of  25,764  lbs.  lias  liecn  attained. 
'I'liis  mixture,  whtai  judiciously  iiianiigtMl  and  duly  proi)ortioncd, 
in(;rcaK»'S  the  r(!sistance  of  cast  iron  iiboiit  one-tliird  -tlie  greatest 
effect  being  obtained  with  a  proportion  of  about  30  l)er  cent,  of 
malleable  iron. 

Jironze  (gun-metal)  varies  in  tenacity  from  23,000  to  54,500 
1>«. 


STRENGTH    OF    MATERIALS. 


121 


Elements  connected  with  the  Tensile  Resistance 
of  various  Substances. 


Substances. 


Beech 

'Jast  iron,  English 

"         American  

Oak 

Steel  plates,  blue  tempered 

"     wire , 

Yellow  pine     , 

Wrought  iron,  ordinary 

"      Swedish 

"      English 

"  "      American 

"  "      wire,  No.  9,  unannealed 

"     annealed... 


fl  _. 

a  ,    , 

•2  Jv, 

'3  2  <B 
-  jS  3 

""  "^  •-"  o 

ID    6'° '2 

io  of 
that 
jrup 

5  0^,5  ® 

|S.2 

Lbs. 

3,355 

.3 

4,00U 

.22 

5,000 

.2 

2,856 

.23 

53,720 

.62 

55,700 

.5 

3,332 

.23 

17,600 

.3 

24,400 

.34 

(  18,850 
]  22,400 

.35 

.35 

15,000 

.56 

47.532 

.46 

36,300 

.45 

Tensile  Strength  of  Materials -Weight  or  Power 
required  to  tear  asunder  one  Square  Inch. 


MISCELLANEOUS  SUBSTANCES. 


Lbs. 


Brick,  well  burned.    . . . 
"       lire 

"      inferior -I 

Cement,  blue  stone 

*'         hydraulic 

"        Harwich 

"        Portland,  6  mo. 

"         Sheppy 

"        Port'd  1,  sand  3 

Chalk 

Glass,  crown 

Gutta-percha 

Hydraulic  lime 

'•  ' '  moiiar. . 

Ivory  

Leather  belts 


750 

65 
290 
100 

77 
234 

30 
414 

24 

380 

118 

2346 

3500 

140, 

140 

16000 

330 


Limestone  

Marble,  Italian 

"        white 

Mortar,  12  years  old. 

Plaster  of  Paris 

Rope,  Manila 

' '      hemj),  tarred . . 

"      wire 

Sandstone,  fine  grain 

Slate  

Stone,  Bath   

"       Craigleth 

"       Hailes 

"      Portland   

Whalebone 


Lbs. 


670 

2800 

5200 

9000 

60 

72 

9000 

15000 

37000 

200 

12000 

352 

400 

360 

857 

1000 

7600 


122 


STRENGTH   OP   MATERIALS. 

METALS. 


Lbs. 

Lbs. 

Copper,  wrought 

34000 

Iron 

plates,  mean,  Eng. 

51000 

rolled 

36(100 

(( 

' '       lengthwise. 

53800 

"        cast,  American. 

24250 

(< 

"       crosswise. . 

48800 

"        wire   

61200 
36800 

inferior  bar 

wire,  Am'n 

30000 

"        bolt 

73600 

Iron,  cast,  Low  Moor.  No.  2. . 

14076 

(( 

"    16dia. 

80000 

"    Clyde,  No.  1 

"      No.  3 

16125 

ti 

scrap 

53400 

23468 

Lead 

,  cast  

1800 

"    Calder,  No.  1 

13735 

(( 

milled 

3320 

"     Stirling,  mean. . . . 

2.-)764 

( ( 

wire 

2580 

"    mean  of  American. 

31829 

Platinum,  wire 

53000 

"    mean*  of  English. 

19484 
45970 

Silve 
Steel 

r,  cast 

40000 

"    Greenwood,  Am'n. 

,  cast,  maximum . . 

142000 

"    gun-metal,  mean. 

37232 

(( 

"     mean 

88657 

"     wrought  wire 

103000 

(( 

blistered,  soft . .  ] 

133000 

"    best  Swedish  bar. 

7-20U0 

104000 

"    Russian  bar 

59500 

H 

sheir 

124000 

"     English  bar 

56000 

n 

chrome,  mean  . . 

170980 

"    rivets,  American. . 

53300 

(< 

puddled,  extreme 

173817 

"    bolts.    

52250 
53913 

it 

Am.  Tool  Co   . . . 

plates,  length  wise 

179980 

"    hammered 

96300 

"    mean  of  English. . 

.•)39()0 

a 

"      crosswise  . 

93700 

'•     rivets,  English.     . 

65000 

(1 

razor  

150000 

'    crank  shaft 

44750 

Tin, 

cast,  block  

5000 

'     turnings 

55800 

n 

Banca 

2122 

"    plates,   boiler,  1 
American \ 

48000 

Zinc 

3500 

62000 

t< 

sheet  

16000 

*  By  Commissioners,  on  application  of  irnu  to  Uailway  Structures. 

Lake  Superior  and  Iron  Mountain  charcoal  bloom  iron  has  re- 
sisted 90,000  lbs.  per  S(|uare  inch. 

COMPOSITIONS. 


Gold  5,  Copper  1. 

BraKH 

"     yellow 

Bron/e,  leiist  . . . . 
"         grotttost. 


Lbs. 


42000 
18000 
17698 
56788 


Copper  10,  Tin  1 

8,  "1,  Riinmrlal 
8,     "1,  unallkir.i 

Tin  10,  Antimony  1    . . 

Yellow  metal 


Lba. 


32000 
:i()0()0 
501)00 
11 1100 
48700 


STRENGTH   OF   MATERIALS^ 

WOODS. 


123 


Lbs. 


Ash 

Beech 

Box 

Bay 

Cedar 

Chestnut,  sweet  . . 

Cypress 

Deal,  Christiana.. . 

Elm   

Lance  

Lignum-vitae 

Locust 

Mahogany 

"         Spanish. 


14000 
11500 
20000 
14000 
1140(1 
10500 

6000 
12400 
13400 
23000 
11800 
20500 
21000 
12000 

8000 


Maple 

Oak,  American  white. 

"     English 

"     seasoned 

"     African 

Pear 

Pine,  pitch 

"      larch 

"      American  white. 

Poplar , 

Spruce,  white 

Sycamore 

Teak     .   

Walnut 

Willow , 


Lbs. 


10500 
11500 
10000 
13600 
14500 

9800 
12000 

9500 
11800 

7000 
10290 
130U0 
14000 

7800 
13000 


Eesults  of  Experiments  on  the  Tensile  Strength  of 
"Wrought-Iron  Tie-Rods. 

Common  Emjllsh  Iron,  1  3-16  inches  in  Diameter. 


Description  of  Connection. 


Breaking  Wght 


Semicircular  hook  fitted  to  a  circular  and  welded 
eye 

Two  semicircular  hooks  hooked  together 

Eight-angled  hook  or  goose-neck  fitted  into  a  cylin- 
drical eye 

Two  links  or  welded  ej'es  connected  together  .... 

.Straight  rods  without  any  connection  articulation . 


Lbs. 

14,000 
16,220 

29,120 
48, 160 
56,000 


Iron  bars  when  cold  rolled  are  materially  stronger  than  when 
only  hot  rolled,  the  difi"erence  being  in  some  cases  as  great  as  3 
to  2. 


Wire  Ropes— Besult  of  Experiments  on  the  Tensile 
Strength  of  Iron  and  Steel  Wire  Ropes. 


Charcoal  Iron 

Wire  Bfipe 

Circum. 


Ins. 

1  T 


Weisht  per 
Foot. 

Breaking 

Wei^-ht. 

steel  Wire 

Rope 

Ci  re  lira. 

stretch  In  6 
Feet. 

Weight  per 

Foot. 

Lbs. 

Lbs. 
13,440 
44,800 

Ins. 

1  15-16 

2| 

Ins. 

If 
1 

Lbs. 

i  ■ 

Breaking 
Wtii-ht. 


Lbs. 
23,600 
36,000 


124 


STRENGTH   OF   MATERIALS. 


Tensile  Strength  of  Copper  at  different  Tem- 
peratures. 


Temp. 

Strenfc-thluU.s. 

1         Temp. 

strength  Inlbs.' I         T.'m|i. 

Strength  In  lbs. 

122° 
212° 
302° 

33,079 
32,187 
30,872 

482° 
545° 
602° 

26,981 

25,420 
22,302 

801° 

912° 

1,016° 

18,854 
14,789 
11,054 

Extension  of  Cast-iron  Bars,  when  suspended 

Vertically. 

1  inch  Square  and  10  feet  in  Lemjih.      iVeighi  applied  at  one  End. 


Weight    '      ,       . 
applied.    Extension. 

Set. 

Weight  ap- 
plied. 

Extension. 

Ins. 
.0397 
.0871 
,1829 

Set. 

Lbs. 

529 

1,058 

2,117 

Ins. 
.0044 
.0092 
.0190 

Ins. 

.000015 
.000059 

Lbs. 
4,234 

8,468 
14.820 

Ins. 
.00265 
.00855 
.02555 

Steel. 

The  tensile  strength  of  steel  increases  by  reheating  and  rolling 
up  to  the  second  operation,  but  decreases  after  that. 


Katio  of  the  Ductility  and  Malleability  of  Metals. 

In  the  order  of 

Wlr-j-drawlng 

Ductility. 

In  tlie  order  of 
I.anilital)le 
Ductility. 

In  the  (irilerof 

Wiie-ii  rawing 

Ductility. 

In  tlie  oriler  of 
I.aTninaltle 
Ductility. 

In  the  order  of 

Wire-drawing 

Ductility. 

In  tlie  order  of 
Lamfiinble 
Ductility. 

Gold. 

Silver. 

Platinum. 

Iron. 

Copper. 

Zinc. 

Tin. 

Lead. 
Nickel. 

Gold. 

Silver. 

Copper. 

Tin. 

Platinum 

Lead. 

Zinc. 
Iron. 
Nickel. 

The  relative  resistance  of  Wrought  Iron  and  Copper  to  tension 
and  compression  is  as  100  to  54.5. 


Transverse  Strength. 

TJie  Transverse  or  I/ileral  Slremith  of  any  Bar,  Beam,  Bod,  etc.,  it 
in  proi)ortion  to  the  product  of  its  breadth  and  the  sijuare  of  its 
deptli;  in  like-sided  beams,  bars,  etc.,  it  is  as  thf  culio  of  tlie 
sidt;,  and  in  cylinders  as  tlie  cube  of  the  diameter  of  tli<!  section. 

IVhen  one  End  is  Jltrd  and  lite  other  jtrojerliitij,  tlie  strength  is  in- 
versely as  tlie  (listaiieti  of  the  weight  from  the  Keetii)n  acted  upon; 
and  th<!  straiu  \\\uni  any  section  is  directly  as  the  distance  of  the 
weiglit  from  tiiat  section. 

When  hoth  Ends  are  fnijiportcd  onli/,  the  strength  is  4  times 
greater  for  an  equal  hngtli,  when  tlie  weight  is  api)lii^d  in  the 
middli!  between  the  suppDrts,  than  if  one  end  only  is  fixed. 

H'lii'n  liitlli  Ends  are jlffd,  tlie  strength  is  (!  times  greater  for  an 
cfpial  length,  wlieii  the  weight  is  applied  in  the  middle,  than  if 
cue  end  only  is  lixej. 


STRENGTH  OF   MATERIALS.  125 

The  strength  of  any  beam,  bar,  etc.,  to  support  a  weight  in  the 
centre  of  it,  when  the  ends  rest  merely  upon  two  supports,  com- 
pared to  one  when  the  ends  are  fixed,  is  as  2  to  3. 

Wkf^n  (he  Weigtd  or  St?-ain  is  uniformly  distribuied,  the  weight  or 
strain  that  can  be  supported,  compared  with  that  when  the 
weight  or  strain  is  applied  at  one  end  or  in  the  middle  between 
the  supports,  is  as  2  to  1. 

In  metals,  the  less  the  dimensions  of  the  side  of  a  beam,  etc., 
or  the  diameter  of  a  cylinder,  the  greater  its  proportionate  trans- 
verse strength :  this  is  in  consequence  of  their  having  a  greater 
proportion  of  chilled  or  hammered  surface  compared  to  their 
elements  of  strength,  resulting  from  dimensions  alone. 

The  strength  of  a  cylinder,  compared  to  a  square  of  like 
diameter  or  sides,  is  as  6.25  to  8.  The  strength  of  a  hollow 
cylinder  to  that  of  a  solid  cylinder,  of  the  same  length  and 
volume,  is  as  the  greater  diameter  of  the  former  is  to  the  diame- 
ter of  the  latter. 

The  strength  of  an  equilateral  triangle,  fixed  at  one  end  and 
loaded  at  the  other,  having  an  edge  up,  compared  to  a  square  of 
the  same  area,  is  as  22  to  27;  and  the  strength  of  an  equilateral 
triangle,  having  an  edge  down,  compared  to  one  with  an  edge 
up,  is  as  10  to  7. 

Note. -In  these  comparisons,  the  beam,  bar,  etc.,  is  consider- 
ed as  one  end  being  fixed,  the  weight  suspended  from  the  other. 
In  Barlow  and  other  authors  the  comparison  is  made  when  the 
beam,  etc  ,  rested  on  supports.    Hence  the  stress  is  contrariwise. 

Bdrusion  is  the  resistance  that  the  particles  or  fibres  of  materi- 
als oppose  to  their  sliding  upon  each  other.  Punching  and 
shearing  are  detrusive  strains. 

Deflection. — When  a  bar,  beam,  etc.,  is  deflected  by  a  cross- 
strain,  the  side  of  the  beam,  etc.,  which  is  bounded  by  the  con- 
cave surface,  is  compressed,  and  the  opposite  side  is  extended. 

In  stones  and  cast  metals,  the  resistance  to  compression  is 
greater  than  the  resistance  to  extension. 

In  woods,  the  resistance  to  extension  is  greater  than  the  re- 
sistance to  compression. 

The  general  law  regarding  deflection  is,  that  it  increases, 
cceferis  paribus,  directlj'  as  the  cube  of  the  length  of  the  beam, 
bar,  etc.,  and  inversely  as  the  breadth  and  cube  of  the  depth. 

The  resistance  of  flexure  of  a  body  at  its  cross-section  is  very 
nearly  9-10  of  its  tensile  resistance. 

The  stiffest  bar  or  beam  that  can  be  cut  out  of  a  cylinder  is 
that  of  which  the  depth  is  to  the  breadth  as  the  square  root  of 
3  to  1 ;  the  strongest,  as  the  squai'e  root  of  2  to  1 ;  and  the  most 
resilient,  that  which  has  the  breadth  and  de^jth  equal. 

Relative  Stiffness  of  Materials  to  Resist  a  Trans- 
verse Strain. 


Ash 

Beech 

Cast  iron    . 

. .     .089 
. .     .073 
. .   1. 

Elm 

Oak   

White  pine  . 

.073 
.095 
.1 

Wrought  iron 
Yellow  pine . . . 

1.3 

.087 

126 


STEENGTH   OF   MATERIALS. 


The  strength  of  a  rectangular  beam  in  an  inclined  position, 
to  resist  a  vertical  stress,  is  to  its  strength  in  a  horizontal  posi- 
tion as  the  square  of  radius  to  the  square  of  the  cosine  of  eleva- 
tion ;  that  is,  as  the  square  of  the  length  of  the  beam  to  the 
square  of  the  distance  between  its  points  of  suijport,  measured 
upon  a  horizontal  plane. 

Exiierimeuts  upon  bars  of  cast  iron,  1,  2,  and  3  inches  square, 
give  a  result  of  transverse  strength  of  HI,  348,  and  338  lbs.  re- 
spectively; being  in  the  ratio  of  1,  .78,  and  .750. 

The  strongest  rectangular  bar  or  beam  that  can  be  cut  out  of 
a  cylinder  is  one  of  which  the  squares  of  the  breadth  and  depth 
of  it,  and  the  diameter  of  the  cylinder,  are  as  1,  2,  and  3  re- 
spectively. 

The  ratio  of  the  crushing  to  the  transverse  strength  is  nearly 
the  same  in  glass,  stone,  and  marble,  including  the  hardest  and 
softest  kinds. 

Green  sand  iron  castings  are  6  per  cent,  stronger  than  dry, 
and  30  per  cent,  stronger  tban  chilled;  but  when  the  castings 
are  chilled  and  annealed,  a  gain  of  115  per  cent,  is  attained 
over  those  made  in  green  sand. 

Chilling  the  under  side  of  cast  iron  very  materially  increases 
its  strength. 

f foods. — Beams  of  wood,  when  laid  with  their  annual  or 
annular  layers  vertical,  are  stronger  than  when  they  are  laid 
horizontal,  in  the  proportion  of  8  to  7. 

Woods  are  denser  at  the  roots  and  at  the  centre  of  their  trunks. 
Their  strength  decreases  with  the  decrease  of  their  density. 

Oak  loses  strength  in  drying. 


Concretes,  Cements,  &c. 


Materials. 


Concretes  (English). 

Fire-brick  beam,  Portland  cement  

"  sand  3  parts,  lime  1  part 

Cements  (English). 
Blue  clay  and  chalk 

Portland | 

Sheppy 

Bricks  (English). 

Best  stock 

Fire-brick 

Now  brick 

Old  brick 

Stock-brick,  well  burned   

"  inferior,  burned 


Breaking 
Weight. 


3.1 

.7 

5.4 
37.5 
10.2 


11^ 

14 

10.7 
9.1 
5.8 
2.5 


STRENGTH  OP  MATERIALS. 


127 


Transverse  Strength  of  Cast  Iron  Bars  and  Oak 
Beams  of  various  Figures. 

Reduced  to  the  uniform  measure  of  one  inch  square  of  secllonal  area,  and 
one  foot  in  length.'   ^xed  at  one  end;  wehjht  suspended  from  the  other. 


Form  of  Bar  or  Beam. 


CAST  IBON. 

Square 

Square,  diagonal  vertical 

Column 


Hollow  column;   greater  diameter  twice  that  of 
lesser , 


Rectangular  prism,  2  in.  deep  X  J  in.  depth .  . 
"  "       3  in.  deep  X  i  in.  depth.  . 

"  "       4  in.  deep  X  i  in.  depth.  . , 


Equilateral  triangle,  an  edge  up. . . 
Equilateral  triangle,  an  edge  down . 


2  in.  deep  X  2  in.  ^-ide  X  -268  in.  depth. 
2  in.  deep  X  2  in.  wide  X  -268  in.  depth. 

OAK. 

Equilateral  triangle,  an  edge  up 

■  Equilateral  triangle,  an  edge  down   .... 


Breaking 
Weicht. 


Lbs. 
873 

568 
573 

794 
1,456 
2,392 
2,652 

560 
958 

2,068 

565 

114 
130 


To  Compute  the  Transverse  Strength  of  a  Rectan- 
gular Beam  or  Bar. 

IF7ie?i  a  Beam  or  Bar  is  fixed  at  one  end  and  haded  at  the  other. 

KuLE. — Multiply  the  value  of  the  material  in  the  preceding 
tables,  or,  as  may  be  ascertained,  by  the  breadth  and  square  of 
the  depth  in  inches,  and  divide  the  product  by  the  length  in  feet. 

Note. — When  the  beam  is  loaded  uniformly  throughout  its 
length,  the  result  must  be  doubled. 

Example.  — What  are  the  weights  each  that  a  cast  and  wrought 
iron  bar,  2  inches  square  and  projecting  30  inches  in  length,  will 
bear  without  permanent  injury? 


128  STRENGTH    OF   MATERIALS. 

The  values  for  cast  and  wrought  iron  in  this  and  the  following 

calculations  are  assumed  to  be  225  and  180. 
Hence  225  X  2  X  2-^  ^  1800,  -^vhich,  —  2.5  =  720  lbs.,  and 
180  X  2  X  2-'  =  1440,  which,  -J-  2.5  =  576  lbs. 

^'  the  Dimeiisions  of  a  Beam  or  Bar  are  r&iuired  to  support  a  given 

loehjhl  at  its  end. 

Rum;.— Divide  the  product  of  the  weight  and  the  length  in 
feet  by  the  value  of  the  material  and  the  quotient  will  give  the 
product  of  the  breadth  and  the  scpiare  of  the  depth. 

Example. — What  is  the  depth  of  a  wrought  iron  beam,  2  inches 
broad,  necessary  to  sujjport  570  lbs.  suspended  at  30  inches  from 
the  fixed  end? 

—  =^  8,  which,  -|-  2  ins.  for  the  brsadth  =  4,  and  \/  4  = 
18U 

2  ins.,  the  depth. 
When  a  Beam  or  Bar  is  fixed  at  both  ends,  and  loadea,  in  the  middle. 

Rule. — Multiply  the  value  of  the  material  by  G  times  the 
breadth  and  the  square  of  the  de^jth  in  inches,  and  divide  the 
product  by  the  length  in  feet. 

Note. — When  the  beam  is  loaded  uniformly  throughout  its 
length,  the  result  must  be  doubled. 

Example. — What  weight  will  a  bar  of  cast  iron,  2  inches  square 
and  5  feet  in  length,  support  in  the  middle,  without  permanent 
inj  ury  ? 

225  X  2  X  C  X  22  =  10800,  which,  -^5  =  2160  lbs. 

Or,  If  the  Dimensions  (f  a  Beam  or  Bar  are  required  to  support  a  given 
iceiglil  in  the  middle  between  tliefi.t('d  ends. 
Rule. — Divide  the  product  of  the  weight  and  the  length  in  feet 
by  6  times  the  value  of  tlie  inutcrial,  and  the  quotient  will  give 
the  product  of  the  breadth  ami  the  sc^uaru  of  the  depth. 

Example.  — What  dimensions  will  a  cast  iron  square  bar,  5  feet 
in  length,  require  to  support  witliout  permanent  injury  a  stress 
of  2,160  lbs.? 

2160  X  5       10800       o       T  •  1      •   o  •        p      XI  A  -i        m 

-  — -  =  =  8,  which,  -r  2  ins.  for  the  assumed  breadth, 
aaO  X  6          louO 

=  4,  and   v^  4  =  2  inches,  the  depth. 

Wlicn  the  Breadth  or  Depth  is  required. 

Rule.— Divide  tlie  j)n)(lnet  obtaint^l  by  the  i)re,ceding  rules  by 
the  sipiaro  of  the  depth,  and  the  (juolient  is  the  breadth;  or  by 
the  breadth,  and  the  square  root  of  the  quotient  is  the  depth. 

Illustration. — If  12S  is  the  jiroduct  and  the  d(q)th  is  8;  then 
128-^ H-J  =  2,  the  breadth.  Also,  128  -^  2  _  64,  and  ^  64  =^ 8, 
the  depth. 

mmi  tJir  irri/jlil  is  not  in  the  middle  hrlirrrn  tlie  ends. 
RuLK.  —  Multiply  the  value  of  the  material  by  3  timos  the  length 


STRENGTH   OF  MATERIALS. 


129 


in  feet,  and  the  breadth  and  square  of  the  depth  in  inches,  and 
divide  the  prodvict  by  twice  the  product  of  the  distances  of  the 
weight  or  stress  from  either  end. 

Example. — What  is  the  weight  a  cast  iron  bar,  fixed  at  both 
ends,  2  inches  square  and  5  feet  in  length,  will  bear  without  per- 
manent injury,  2  feet  from  one  end? 

225X3  X5X  2  X2V    27000 ^2,2501bs. 


2X2X3 


12 


Transverse  Strength  of  Solid  and  Hollow  Cylin- 
ders of  various  Materials. 

One  foot  in^length.     Fixed  at  one  end;  weight  suspended  from  the  other. 


Materials. 


■WOODS. 

Ash 

Fir*.   .......  ....  .... 

White  pine 

METAL. 

Cast  iron,  cold  blast.  .  . 

STONE-WAKE. 

Kolled  pipe  of  fine  clay 


Solid 
External 
Diameter 

Hollow 
Interual 
Diameter 

Breaking 
Weight. 

lus. 

lus. 

Lbs. 

2. 
2. 
2. 
1. 
2. 

1. 

685 
604 
772 
75 
610 

3 

— 

12,000 

2.87 

1.928 

190 

Breaking  Weight 
for  1  in.  external 
diam  ,  and  pro- 
portionate inter- 
nal diameter. 


Lbs. 
86 
75 
97 

75 
76 

444 


*  An  inch-square  batten,  from  the  same  plank  as  this  specimen,  broke  at 

139  lbs. 


Brick-Work. 

A  brick  arch,  having  a  rise  of  2  feet,  a  span  of  15  feet  9  inches, 
and  2  feet  in  width,  with  a  depth  at  its  crown  of  4  inches,  bore 
358,400  lbs.  laid  along  its  centre. 


Girders,  Beams,  Lintels,  etc. 

77te  Trnnverse  or  Lateral  Strength  (f  any  Girder,  Beam,  Brest-sum- 
mer, Linlel,  etc.,  is  m  proportion  to  the  product  of  its  breadth  and 
the  square  of  its  depth,  and  also  to  the  area  of  its  cross-section. 

The  best  form  of  section  for  cast  iron  girders  or  beams,  etc.,  is 
deduced  from  the  experiments  of  Mr.  E.  Hodgkinson,  and  such 
as  have  this  form  of  section  X  are  known  as  Hodgkinson's. 

The  rule  deduced  from  his  experiments  directs  that  the  area  of 
the  bottom  flange  should  be  6  times  that  of  the  top  flange — flanges 
connected  by  a  thin  vertical  web,  sufficiently  rigid,  however,  to 

6* 


130  STRE^'GTH   OP   MATERIALS. 

give  the  requisite  lateral  stiffness,  and  tapering  both  upward  and 
downward  from  the  neutral  axis;  and  in  order  to  set  aside  the 
risk  of  an  imperfect  casting,  by  any  great  disproportion  between 
the  web  and  the  flanges,  it  should  be  tapered  so  as  to  connect 
with  them,  with  a  thickness  corresponding  to  that  of  the  flange. 

As  both  cast  and  wrought  irou  resist  crusliing  or  compression 
with  a  greater  force  than  extension,  it  follows  that  the  flange  of  a 
girder  or  beam  of  either  of  these  metals,  which  is  subjected  to  a 
crushing  strain,  according  as  the  girder  or  beam  is  supported  at 
both  ends,  or  fixed  at  one  end,  should  be  of  less  area  than  the 
other  flange,  which  is  subjected  to  extension  or  a  tensile  strain. 

When  girders  are  suVtjected  to  impulses,  and  are  used  to  siistain 
vibrating  loads,  as  ia  bridges,  etc.,  the  best  jn'oportion  between 
the  top  and  bottom  flange  is  as  1  to  4  ;  as  a  general  rule,  they 
should  be  as  narrow  and  deep  as  practicable,  and  should  never 
be  deflected  to  more  than  one  five-hundredth  of  their  length. 

In  public  halls,  churches,  and  buildings  where  the  weight  of 
people  alone  is  to  be  provided  for,  an  estimate  of  175  pounds  per 
square  foot  of  floor  surface  is  sufticient  to  provide  for  the  weight 
of  the  flooring  and  the  load  upon  it. 

In  churches,  buildings,  etc.,  the  weight  to  be  provided  for 
shoiald  be  estimated  at  that  which  may  at  any  time  be  placed 
thereon,  or  which  at  any  time  may  bear  upon  any  portion  of 
their  floors;  the  usual  allowance,  however,  is  for  a  weight  of  280 
lbs.  per  square  foot  of  floor  surface  for  stores  and  factories,  and 
175  lbs.  per  square  foot  when  the  weight  of  people  alone  is  to  be 
provided  for. 

In  all  uses,  such  as  in  buildings  and  bridges,  where  the  struc- 
ture is  exposed  to  sudden  impulses,  the  load  or  stress  to  be  sus- 
tained should  not  exceed  from  1-5  to  1-6  of  the  breaking  weight 
of  the  material  employed;  but  when  the  load  is  uniform  or  the 
stress  quiescent,  it  may  be  increased  to  1-3  or  1-1  of  the  breaking 
weight. 

Aja  open-web  girder  or  beam,  etc.,  is  to  be  estimated  in  its  re- 
sistance on  tlio  same  principle  as  if  it  had  a  solid  web.  In  cast 
metals,  aUowance  is  to  be  made  for  the  loss  of  strength  due  to  the 
unequal  contraction  in  cooling  of  the  web  and  flange.s. 

In  cast  iron,  the  mean  resistance  to  crushing  or  extension  is  as 
3.6  to  1,  and  in  wrought  iron  as  1  to  1.3;  lience  the  luass  of  metal 
below  the  neutral  axis  will  be  greatest  in  these  proijortions  when 
the  stress  is  intermediate  between  the  ends  or  supi)orts  of  the 
giril(;rs,  etc. 

\V<j<xl-n  Ginlrrs  or  Beams,  when  sawed  in  two  or  more  pieces, 
and  have  slijis  set  between  them,  and  tlio  whole  bolted  together, 
are  made  stiiferby  the  oixration,  and  are  rendered  less  liable  to 
deriiiy. 

Girders  east  witli  ii  fiuui  up  are  stronger  than  when  cast  on  a 
sidi',  in  the  jiroportion  of]  to  .!t(i,  mid  tliey  iire  strongest  also 
wlien  cast  with  tlie  bottoiti  iliiugc!  up. 

Tlie  following  results  of  tlie  resistances  of  metals  will  show 
how  the  material  should  bo  (listrii)uted  in  onler  to  obtain  the 
maxinnuu  of  strength  with  the  minimum  of  material  : 


STRENGTH    OP   MATERIALS. 


131 


Cast  Iron 

CopiDer 

Wrought  iron 


To  Tension. 

To  Crushing. 

(  21,(100 
1  32,000 

90,300 

140,500 

24.250 

117,000 

j  45,000 

40,000 

1  72,000 

83,000 

The  best  iron  has  the  greatest  tensile  strength,  and  the  least 
compressive  or  crushing. 

The  most  economical  construction  of  a  girder  or  beam,  with 
reference  to  attaining  the  greatest  strength  with  the  least  mate- 
rial, is  as  follows:  The  outline  of  the  top,  bottom,  and  sides  should 
be  a  curve  of  various  forms,  according  as  the  breadth  or  the 
depth  throughout  is  equal,  and  as  the  girder  or  beam  is  loaded 
only  at  one  end,  or  in  the  middle,  or  uniformly  throughout. 


To  Compute  the  Dimensions  and.  Form  of  a  Girder 

or  Beam. 

When  a  Girder  or  B  am  is  Ficed  at  om  End  and  Loaded  at  the  other. 

1.  When  the  Depth  is  unifo  m  throughout  the  entire  Length,  The 
section  at  every  point  must  be  in  propoi'tion  to  the  product  of 
the  length,  breadth,  and  square  of  the  dejjth,  and  as  the  square 
of  the  depth  is  in  every  point  the  same,  the  breadth  must  vary 
directly  as  the  length;  consequently,  each  side  of  the  beam  must 
be  a  vertical  plane,  tapering  gradually  to  the  end 

2.  When  the  Briadth  is  uniform  throughout  the  entire  Length,  The 
depth  must  vary  as  the  square  root  of  the  length;  hence  the 
upiier  or  lower  sides,  or  both,  must  be  determined  by  a  parabolic 
curve. 

3.  When  the  Section  at  every  point  is  similar — that  is,  a  Circle,  an 
Ellipse,  a  Square,  a  Rectangle,  the  sides  of  which  bear  a  fixed  pro- 
portion to  each  other.  The  section  at  every  point  being  a  regialar 
figure,  for  a  circle,  the  diameter  at  every  point  must  be  as  the 
cube  root  of  the  length;  and  for  an  ellipse,  or  a  rectangle,  the 
breadth  and  depth  must  vary  as  the  cube  root  of  the  length. 

When  a  Girder  or  Beam  is  Fixed  at  one  End,  and  Loaded  uniformly 
throughout  its  Length. 

1.  When  the  Depth  is  uniform  throughout  its  entire  Length,  The 
breadth  must  increase  as  tlie  square  of  the  length. 

2.  When  the  Breadth  is  uniform  throughout  its  entire  L^ength,  The 
depth  will  vary  directly  as  the  length. 

3.  When  the  Sec  ion  at  everij  point  is  similar,  as  a  Circle,  EUipse, 
Square,  and  Rectangle,  The  section  at  every  point  being  a  regular 
figure,  the  ciabe  of  the  depth  must  be  in  the  ratio  of  the  square 
of  the  length. 

When  a  Girder  or  Beam  is  Supported  at  both  Ends. 
1.   When  Loaded  in  the  Middle,  The  constant  of  the  beam,  or  the 


132  STRENGTH    OF   MATERIALS. 

l)ri)duct  of  the  breadth  and  the  square  of  the  depth,  must  he  in 
proportion  to  the  distance  from  the  nearest  support  ;  eonse- 
(iuentlj%  whether  the  lines  forming  the  beam  are  straight  or 
curved,  they  meet  in  the  centre,  and  of  course  the  two  halves  are 
alike;  the  beam,  therefore,  may  be  considered  as  one  of  half  the 
length,  the  supported  end  corresponding  with  the  free  end  in 
the  case  of  beams,  one  end  being  fixed,  and  the  middle  of  the 
beams  similarly  corresponding  with  the  fixed  end. 

2.  When  the  Deplh  is  xiniform  throwjhout,  The  breadth  must  be  in 
the  ratio  of  the  length. 

3.  When  the  Breadlh  is  uniform  throughout,  The  depth  will  vary 
as  the  square  root  of  the  length. 

4.  When  the  Section  at  every  point  is  similar,  as  a  Circle,  Ellipse, 
Square,  and  Itectanfjle,  The  section  at  every  point  being  a  regular 
figure,  the  cube  of  the  depth  will  be  as  the  square  of  the  distance 
from  the  sujiported  end. 

When  a  Girder  or  Beam  is  Supported  at  both  Ends,  and  Loaded 
uniform' y  tkroiujliout  its  Length. 

1.  When  tlie  Di-plh  is  wii form,  The  breadth  will  be  as  the  pro- 
duct of  the  length  of  the  beam  and  the  length  of  it  on  one  side 
of  the  given  point,  less  the  square  of  the  length  on  one  side  of 
the  given  point. 

2.  When  the  Breadth  w  uniform.  The  depth  will  be  as  the  square 
root  of  the  product  of  the  length  of  the  beam  and  the  length  of 
it  on  one  side  of  the  given  point,  less  the  square  of  the  length  on 
one  side  of  the  given  point. 

3.  When  the  Section  at  every  point  is  similar,  as  a  Circle,  Ellipse, 
Sqiuire,  and  llertamjle,  The  section  at  every  point  being  a  regular 
figure,  the  cube  of  the  depth  will  be  as  the  i)r()dnct  of  the  length 
of  the  beam  and  the  length  of  it  on  one  side  of  the  given  i)oint, 
less  the  square  of  the  length  on  one  side  of  the  given  point. 

Genebal  Deductions  from  the  Experiments  of  Stephenson, 
Fairbairn,  Cubitt,  Hughes,  etc. 

Fairbairn  shows  in  his  experiments  that  with  a  stress  of  about 
12,320  Iks.  per  S(iuare  inch  on  cast  iron,  and  28,000  lbs  on  wrought 
iron,  the  sets  and  elongations  are  nearly  etpial  to  eaidi  other. 

A  cast  iron  beam  will  be  bent  to  one-third  of  its  breaking 
weight  if  the  load  is  laid  on  grudiialiy ;  and  one-sixth  of  it,  if  laid 
on  at  once,  will  i)rodiice  the  saiiif  effect,  if  tlie  weight  of  tin;  beam 
is  small  compan'<l  with  the  wciglit  laid  on.  Hence  beams  of  cast 
iron  should  l)e  made  ca])al)le  of  bearing  more  than  0  times  the 
greatest  weiglit  wliich  will  be  laid  uj)on  them. 

In  l>eams  of  castor  wrought  iron  tlio  flanges  should  be  propor- 
tionate to  the  relative  crushing  and  tensile  resistances  of  the  mo- 
t<rial. 

The  breaking  weights  in  similar  beams  are  to  each  other  as  the 
BquareH  of  their  like  linear  dimensions;  that  is,  the  breaking 
weights  of  l)eams  are  coinpiited  by  multiplying  togetluir  the  area 
of  their  section,  their  depth,  and  a  constant,  determined  from 


STRENGTH   OP   MATERIALS.  133 

experiments  on  beams  of  the  particular  form  under  investigation, 
and  dividing  the  product  by  the  distance  between  the  supjiorts. 

Cast  and  wrought  iron  beams,  having  similar  resistances,  have 
weights  nearly  as  2.44  to  1. 

The  range  of  the  comparative  strength  of  girders  of  the  same 
depth,  having  a  top  and  bottom  flange,  and  those  having  bottom 
flange  alone,  is  from  having  but  a  little  area  of  bottom  flange  to 
a  large  proportion  of  it,  from  1-2  to  1-4  greater  strength. 

A  box  beam  or  girder,  constructed  of  plates  of  wrought  iron, 
compared  to  a  single  rib  and  flanged  beam  X,  of  equal  weights, 
ha.s  a  resistance  as  100  to  93. 

The  resistance  of  beams  or  girders,  where  the  depth  is  greater 
than  their  breadth,  when  supported  at  top,  is  much  increased. 
In  some  cases  the  difi'erence  is  fully  one-third. 

When  a  beam  is  of  equal  thickness  throughout  its  depth,  the 
curve  should  be  an  ellipse  to  enable  it  to  support  a  uniform  load 
with  equal  resistance  in  every  part;  and  if  the  beam  is  an  open 
one,  the  curve  of  equilibrium  for  a  uniform  load  should  be  that  of 
a  parabola.  Hence,  when  the  middle  portion  is  not  wholly  re- 
moved, the  curve  should  be  a  compound  of  an  ellipse  and  a  pa- 
rabola, approaching  nearer  to  the  latter  as  the  middle  part  is  de> 
creased. 

Girders  of  cast  iroa,  up  to  a  span  of  40  feet,  involve  a  less  cost 
than  of  wrought  iron. 

Cast  iron  beams  and  girders  should  not  be  loaded  to  exceed  one- 
fifth  of  their  breaking  weight;  and  when  the  strain  is  attended  with 
concussion  and  vibration,  this  proportion  must  be  increased. 

Simple  cast-iron  girders  may  be  made  50  feet  in  length,  and 
the  best  form  is  that  of  Hodgkihson;  when  subjected  to  a  fixed 
load,  the  flange  should  be  as  1  to  6,  and  when  to  a  concussion, 
etc.,  as  1  to  4, 

The  forms  of  girders  for  spaces  exceeding  the  limit  of  those  of 
simple  cast  iron  are  various;  the  principal  ones  adopted  are  those 
of  the  straight  or  arched  cast-iron  girders  in  separate  pieces,  and 
bolted  together — the  Trussed,  the  Bow-string,  and  the  wrought 
iron  Box  and  Tubular. 

A  StraiijM  or  Archeil  Girder  is  formed  of  separate  castings,  and 
is  entirely  dependent  ujion  the  bolts  of  connection  for  its  strength. 

A  Trussed  or  Bow-siring  Girder  is  made  of  one  or  more  castings 
to  a  single  piece,  and  its  strength  depends,  other  than  upon  the 
depth  or  area  of  it,  iipon  the  proper  adjustment  of  the  tension, 
or  the  initial  strain,  upon  the  wrought  iron  truss. 

A  Box  or  Tubular  Girder  is  made  of  wrought  iron,  and  is  best 
constructed  with  cast  iron  tops,  in  order  to  resist  compression; 
this  form  of  girder  is  best  adapted  to  afford  lateral  stiffliess. 


Floor  Beams,  Girders,  etc. 

The  condition  of  the  stress  borne  by  a  floor  beam  is  that  of  a 
beam  supported  at  both  ends  and  uniformly  loaded;  and  from  the 
irregularity  in  its  loading  rmd  unloading,  and  from  the  necessity 


134  STRENGTH   OF   MATERIALS. 

of  its  possessing  great  rigidity,  it  is  impracticable  to  estimate  its 
capacity  other  thaa  as  a  beam  having  the  weight  borne  upon  the 
middle  of  its  length. 

To  Compute  the  Depth  of  a  Floor  Beam. 

When  the  Length  ami  Breadth  are  rjiv  n,  and  the  Distance  hdween  th« 
CetUres  of  the  Beam  is  One  Foot. 

EuLE.— Divide  the  product  of  the  square  of  the  length  in  feet 
and  the  weight  to  be  borne  in  pounds  per  sqiiare  foot  of  floor,  l)j' 
the  product  of  -4  times  the  breadtli  and  the  value  of  the  material, 
and  the  square  root  of  the  quotient  will  give  the  depth  of  the  beam 
in  inches. 

Example. — A  white  pine  beam  is  two  inches  wide,  and  12  feet 
in  length  between  the  sup{)orts;  what  should  be  the  depth  of  it 
to  support  a  weight  of  175  lbs.  per  s(|uare  foot? 

12-  y  175 

„     .     '    =  105,  and  y  105  =  10.25  ins. 
2X4X30  ^ 

When  the  Distance  Ijetween  the  Cn^res  of  the  Beam  is  greater  or  less 

than  One  Foot. 

EuLE. — Divide  the  product  of  the  square  of  the  depth  for  a 
beam,  when  the  distance  between  the  centres  is  one  foot,  by  the 
distance  given  in  inches  by  12,  and  the  square  root  of  the  quo- 
tient will  give  the  depth  of  the  beam  in  inches. 

Example. — Assume  the  beam  in  the  preceding  case  to  be  set  15 
ins.  from  the  centres  of  its  adjoining  beams,  what  should  be  its 
depth  ? 

10.25y  15  ^  j2^  25,  and  v'  131.25  =  11.45  ins. 


Header  and  Trimmer  Beams. 

The  conditions  of  the  stress  borne  or  to  be  provided  for  by 
them  are  as  follows  : 

Header  or  Trimmer  beams  support  half  of  the  weight  of  and 
upon  the  tail  beams  inserted  into  or  attached  to  them. 

Trimmer  Beams  support,  in  addition  to  that  borne  by  them  di- 
rectly as  a  floor  beam,  each  half  tlu;  wciglit  on  the  headers. 

The  stress,  therefore,  ujiou  a  header  is  due  directly  to  its  length, 
or  the  number  of  tail  beams  it  supports;  and  the  stress  upon  tlio 
trimmer  beams  is  that  of  their  own  stress  as  a  floor  beam,  and 
half  of  the  weight  upon  the  header  supjiorted  by  them. 

Note.  -The  distance  between  the  sup])ort  of  the  trimmer  beams 
and  the  point  of  connection  with  the  header  does  not  in  anywise 
afr<tet  the  stress  u))on  the  trimmer  beams;  for  in  just  j)roportion 
as  tills  distance  is  increased,  and  the  stress  ujion  tliem  conse- 
<iniiitly  iiK^reased,  by  the  suspension  of  the  headier  from  them 
nearer  to  the  middle  of  tiuir  length,  so  is  the  area  of  tlie  surface 
HU])pt)rted  l>y  thc!  header  reduced,  an<l,  consequently,  the  load 
to  bo  borno  by  it. 


STRENGTH   OF   MATERIALS. 


135 


Transverse  Strength  of  Cast  Iron  Girders  and  Beams,  deduced  from 
the  Experiments  of  Barlow,  Hodgkinson,  Hughes,  Tredgold, 
Taylor,  etc. 

Redticed  to  a  uniform  measure  of  one  inch  in  depth,  one  foot  in  length,  supported  at 
both  ends  ;  the  stress  nr  weight  applied  in  the  middle. 


Section 

or  GiRDEB  OR 

Beam. 


Flanges. 


o 
H 


Eq.  area  "1 

I  of  flange  I 

attopaud  j 

'    bottom,  J 

I  ^°-  I 
Arpa  of  1 
sec.  of  I 
top  and  }• 
bot.  1 
1  to  6,    J 


Sq.  Ins. 

1.75X  42 
=  .735 

'>.02x.rA5 
=  1.040 


2.23X.31 
=  .72 


5x.3=1.6 


a 

o 

■*^ 

o 

« 

Sq.  Ins. 

1.77x,3'J 
=  .G9 

2  02x  515 
=1.040 


r,.(;7x  06 
=  1.4 


jx.3=1.5 


Eectangii- 
lar  PriBm, 


Open 
Beam, 


^^    Square 
liJ     Prism, 

WJ   Column, 

,A.     Square 
"^M^    Prism, 
anjilfi  up. 


5x.5=.25 

1.5x5= 
.75 

4x2=8 


5.1x2.33 
=  ll.d8 


1  005  X.98 
.995x1.01 
1.005  x.98 
.771x1.51 
1.507  X  74 
1.525  X.  78 


23.9x3.12 
=  74.56 

l..'=x.6= 
.75 

.5x5  = 
.25 


12.1x2  07 
=  25  04    2.08 

.994 
1  005x99' 1.00.- 


In. 

.29 
.51' 

.206 

.36i 
.365 

3.3 

.5 


■d 
u 

3 

Cm 

o 

Qi 

Q 


.995 x.l 
1.005  X.  99 
.771x1.5 
1.507  X.74 


.995 
1.00 

.771 
1  .507 


1. 525  X.  78: 1.525 
11.02 


1.122 
1.443 


In. 
5.125 
2.02 

5.125 

1.56 
1.56 

56.1 

4.t 
4.t 
4. 

30.5 

2.012 

2./51 

3.01 

4 

4  04 

4.04 

4.07 

1.02 

1.122 

1.443 


■a 


o 
si 
-a 

03 


In. 

1.77 
2.02 

6.67 

5. 
5. 

23.9 

1.5 
1.5 


a 

o 

OQ  c 


11.1 

994 

005 

995 

1  005 


Sq.I. 
2.82 
2  59 

6.23 

1.96 
1.96 

183.5 

1. 

1. 

12. 

90.8 

2.025 
I  98 
1.9S 


5§ 
'©  VI 

a  a    . 

■3;::  § 


Lbs. 

301-'>0 
10276 

117450 

7280 
2360 

80G624f 

19980 

7252 


g.a 


Lbs 


a>  bo 

3  a 
s  ■"■ 
>■ 

Lbs 


10768  6100 
1900 


3952 

188.J2 

3714 
:213 

43958 

19980 
7252 


3^600    2800 

479380052795 
9440    4662 


.771  2.-2. 
1.. 507  2.23 
1.525  2.35 


1  02 


1.122 


1.03 


.989 


1.443  1.041 


12340 
154211 
2170.5 
2.-)705 
25735 
30000 

263.=. 


2370 
2269 


6232 

7710 
10992 
11070 
11540 
12689 


i6S0 

2350 
760 

1200 

.5000 

1800 

700 

1700 

2350 

2460 
2550 
2700 
2750 
2850 
3100 


2552;  2500 
2396  2150 
2182  1500 


♦  Horizontal  yreb. 


t  Deptti  of  opening,  3  J  iicheB. 


136  STRENGTH   OF   MATERIALS. 


General  Deductions. 

In  cast  iron,  the  permanent  deflection  is  from  one-third  to 
one-quarter  of  its  breaking  weight,  and  the  deflection  should 
never  exceed  one-third  of  the  ultimate  deflection. 

All  rectangular  bars  of  wrought  iron,  having  the  same  bearing 
length,  and  loaded  in  their  centre  to  the  full  extent  of  their 
elastic  power,  will  be  so  deflected,  that  their  deflection,  being 
multiplied  by  their  depth,  the  product  will  be  a  constant  quan- 
tity, whatever  may  be  their  breadth  or  other  dimensions,  pro- 
vided their  lengths  are  the  same. 

The  heaviest  running  weight  that  a  bridge  is  subjected  to  is 
that  of  a  locomotive  and  tender,  which  is  equal  to  1.5  tons  per 
lineal  foot. 

Girders  should  not  be  deflected  to  exceed  the  one  fortieth  of 
an  inch  to  a  foot  in  length. 

In  cast  iron,  the  one-twentieth  to  one-thirtieth  of  the  breaking 
weight  will  gi\  e  a  visible  set. 

When  a  load  on  a  girder  is  supported  by  the  bottom  flange  of 
it  alone,  it  produces  a  torsional  strain. 

A  continuous  weight,  equal  to  that  a  beam,  etc.,  is  suited 
to  sustain,  will  not  cause  the  deflection  of  it  to  increase  unless  it 
is  subjected  to  considerable  changes  of  temperature. 

The  heaviest  load  on  a  railway  girder  should  not  exceed  one- 
sixth  of  that  of  the  breaking  weight  of  the  girder  when  laid  on 
at  rest. 

Deflection  consequent  upon  Velocity  of  the  Load. — Deflection  is  very 
much  increased  by  instantaneous  loading;  by  some  authorities 
it  is  estimated  to  be  doubled. 

The  momentum  of  a  railway  train  in  deflecting  girders,  etc.,  is 
greater  than  the  eff"ect  from  the  dead  weight  of  it,  and  the  de- 
flection increases  with  the  velocity. 

Exi)erimcnts  made  by  the  Commissioners  of  Railway  Structures 
of  1849,  showed  that  a  i)assing  load  produced  a  greater  efiect  on 
a  beam  than  a  load  at  rest. 

A  carriage  was  moved  at  a  velocity  of  10  miles  per  hour;  the 
deflection  was  .8  inch,  and  when  at  a  velocity  of  30  miles' the  do- 
fl(H;tion  was  \\  inches. 

In  this  case,  4  l.'JO  lbs.  would  have  boon  the  breaking  weight 
of  the  bars  if  applied  in  their  middle,  but  1,778  lbs.  -would  have 
broken  them  if  pa.ssed  over  them  with  a  velocity  of  30  miles  per 
hour. 

Cast  iron  will  bend  to  one-third  of  its  ultimate  deflection  with 
less  than  one-tliird  of  its  ])reaking  weight  if  it  is  laid  on  gnidually, 
and  but  one-sixth  if  laiil  on  rapidly. 

When  motion  is  given  to  the  load  on  a  beam,  etc.,  the  point  ol 
greate>it  (lefb'ction  does  not  remain  in  the  centre  of  the  beam, 
etc.,  as  beuiMS  broken  by  a  travelling  load  are  always  fractured  at 
points  beyond  their  centreH,  nrul  oft«!n  into  several  jiieces. 

Chilled  bars  of  oust  iron  deflect  more  readily  than  unchillod. 


STRENGTH   OF   MATERIALS.  13'< 

Kesults  of  Experiments  on  the  Subjection  of  Iron 
Bars  to  Continual  Strains. 

Cast  iron  bars  subjected  to  a  regular  depression,  equal  to  the 
deflection  due  to  a  load  of  one-third  of  their  statical  breaking 
weight,  bore  1U,(jOO  successive  depressions,  and  when  broken  by 
statical  weight  gave  as  great  a  resistance  as  like  bars  subjected  to 
a  like  deflection  by  statical  weight. 

Of  two  bars  subjected  to  a  deflection  equal  to  that  carried  by 
half  of  their  statical  breaking  weight,  one  broke  with  28,602  de- 
pressions, and  the  other  bore  30,000,  and  did  not  appear  weaken- 
ed to  resist  statical  pressure. 

Hence  cast  iron  bars  will  not  bear  the  continual  applications 
of  one-third  of  their  breaking  weight. 

A  bar  of  wrought  iron,  2  inches  square  and  9  feet  in  length  be- 
tween its  supports,  was  subjected  to  1(10,000  vibrator}'  depressions, 
each  equal  to  the  deflection  due  to  a  load  of  tive-ninths  of  that 
which  permanently  injured  a  similar  bar,  and  their  depressions 
only  produced  a  permanent  set  of  .015  inch. 

The  greatest  deflection  which  did  not  produce  any  permanent 
set  was  due  to  rather  more  than  one-half  the  statical  weight, 
which  permanently  injured  it. 

A  wrought-iron  box  girder  6x6  inches  and  9  feet  in  length, 
was  subjected  to  vibratory  dejiressions,  and  a  strain  correspond- 
ing to  3,762  lbs.,  repeated  43, 370  times,  did  not  produce  any  ap- 
preciable effect  on  the  rivets. 

Mr.  Tredgold,  in  his  experiments  upon  cast  iron,  has  shown 
that  a  load  of  30')  lbs.,  suspended  from  the  middle  of  a  bar  1 
inch  square  and  34  inches  between  its  siipports.  gave  a  deflection 
of  .16  of  an  inch,  while  the  elasticity  of  the  metal  remained  im- 
impaired.  Hence  a  bar  1  inch  square  and  1  foot  in  length  will 
sustain  650  lbs.,  and  retain  its  elasticity 


Torsional  Strength. 

The  Torsional  Strength  of  any  square  bar  or  beam  is  as  the  cube 
of  its  side,  and  of  a  cylinder  as  the  ciibe  of  its  diameter.  Hollow 
cylinders  or  shafts  have  greater  torsional  strength  than  solid 
ones  containing  the  same  volume  of  material. 

The  Torsional  Awjh  of  a  bar,  etc.,  under  equal  pressures  will 
vary  as  the  length  of  the  bar,  etc.  Hence  the  torsional  strength 
of  bars  of  like  diameters  is  inversely  as  their  lengths. 

The  strength  of  a  cylindrical  prism  compared  to  a  square  is 
as  1  to  .85. 

When  a  bar,  beam,  etc.,  having  a  length  greater  than  its 
diameter,  is  subjected  to  a  torsional  strain,  the  direction  of  the 
greatest  strain  is  in  the  line  of  the  diagonal  of  a  square,  and  if  a 
square  be  drawn  on  the  surface  of  the  bar,  etc.,  in  its  primitive 
form,  it  will  become  a  rhombus  by  the  action  of  the  strain. 


138  STBENGIH   OF   MATERIALS. 

To  Compute  the  Diameter  of  a  Square  or  Bound 
Shaft,  etc.,  to  resist  Torsion. 

KuL,E. — Multiply  the  extreme  of  pressure  ui>on  the  crank-pin, 
or  at  the  pitch-line  of  the  pinion,  or  at  the  centre  of  effect  upon 
the  blades  of  the  wheel,  etc.,  that  the  shaft  may  at  any  time  be 
subjected  to,  by  the  length  of  the  crank  or  radius  of  the  wheel, 
etc.,  in  feet;  divide  their  product  by  the  value,  and  the  cube  root 
of  the  quotient  will  give  the  diameter  of  the  shaft  or  its  journal 
in  inches. 

Example. — What  should  be  the  diameter  for  the  journal  of  a 
wrought-iron  water-wheel  shaft,  the  extreme  pressure  upon  the 
crank-pin  being  59,4.00  lbs.,  and  the  crank  5  feet  in  length? 

?^i^?^^  =  2,376, and  V  2,276  =  13.31  inches. 
125 

When  two  Shajts  are  used,  as  in  Sieamrvessels  loHh  one  Engine,  etc 

Uttle. — Divide  three  times  the  cube  of  the  Cameter  for  one 
shaft  by  four,  and  the  cube  root  of  the  quotient  T.ill  give  the  di- 
ameter of  the  shaft  in  inches. 

Example. — The  area  of  the  journal  of  a  shaft   is  113   inches; 
what  should  be  the  diameter,  two  shafts  being  used  ? 
Diameter  for  area  of  113  =  12. 

Then  A>li^  =.  1,296,  and' s/  1,296  =  10.9  inches. 


Note. — The  examples  here  given  are  deduced  from  instances 
of  successful  practice;  where  the  diameter  has  been  less,  fracture 
has  almost  universally  taken  place,  the  strain  being  increased 
beyond  the  ordinary  limit. 

When  the  work  to  be  performed  is  of  a  regular  character,  and 
the  stress  is  consequently  uniform,  the  proportion  of  J  may  be 
reduced  to  f. 

Kelative  Values  of  Diameters. 

When  shafts  of  less  diameter  than  12  inches  are  required,  the 
values  here  given  may  be  slightly  reduced  or  increjised,  accord- 
in"  to  the  quality  of  the  iron  and  the  <liameter  of  the  shaft  to  be 
used,  Vjut  when  tliey  exceed  this  diameter,  the  values  may  not  bo 
increased,  as  the  strength  of  a  cast  or  wrought  iron  shaft  decreases 
very  materially  a.s  its  diameter  increases. 

To  Compute  the  Torsional  Strength  ol  Hollow 
Shafts  and  Cylindcra. 

Rni.K — From  the  fourth  power  <if  the  exterior  diainttor  sul)- 
tract  the  fourth  power  of  the  interior  diameter,  anci  multiply  tlie 
remaimler  l)y  the  value  of  the  material;  divide  this  product  by 
the  product  of  tlie  exterior  diameter  and  the  Icngtli  or  distance 
from  the  axis  at  which  tho  atr'ss  is  applied  in  feet;  the  quotient 
will  give  the  resistance  in  pounds. 


STRENGTH   OF   MATERIALS. 


139 


Example. — What  torsional  stress  may  be  borne  by  a  cast-iron 
hollow  shaft,  having  diameters  of  3  and  2  inches,  the  power  being 
applied  at  i  foot  from  its  axis  ? 


3^  —  2^X105  =  81 


:  6,825,  which -i-  3  X  1  =  -^  = 


16X105: 

2,275  lbs. 
The  order  of  shafts,  with  reference  to  the  degree  of  torsional 


stress  to  which  they  are  subjected,  is  as  follows  : 


1.  Fly-wheel. 

2.  Water-wheel. 


3.  Secondary. 

4.  Tertiary,  etc. 

Hence  the  diameters  of  their  jonmals  may  be  reduced  in  this 
order. 


Kesults  of  Experiments  upon  the  Detrusive 
Strength  of  Metals  with  Shears. 

Made  by  Pabat.t.et.  CtrriERs. 

Wrought  Iron. — Thickness  from  .5  to  1  inch,  50,000  lbs.,  per 
square  inch. 

Made  by  Inclined  Cuttees,  angle  1  in  8  =  7'. 


Sheet  Metals. 

Thicknesa, 

Power. 

Bolts. 

Diameter. 

rower. 

Brass 

Ckjpper 

Ins. 
.03 
.297 

.24 
.51 
1. 

Lbs. 
540 

11,196 

Brass 

Copper 

Ids. 
1.11 
.775 

.775 

1.142 

.32 

Lbs. 

29,700 
11,310 
28,720 
35,410 
3,093 

Steel 

14,930 
39,150 
44,800 

Steel 

Wrought  iron,  j 

Wrought  iron .  | 

The  resistance  of  wrought  iron  to  shearing  is  about  75  per 
cent,  of  its  resistance  to  tensile  stress. 

The  resistance  to  shearing  of  plates  and  bolts  is  not  in  a  direct 
ratio.  It  approximates  to  that  of  the  square  of  the  depth  of  the 
former,  and  to  the  square  of  the  diameter  of  the  latter. 


Character  of  Strains  to  which  Connecting  Kods, 
Straps,  Gibs,  and  Keys  are  subjected. 

Heads  of  Mods.— At  sides  of  keyholes,  tensile  and  crush- 
ing; at  front  of  keyholes,  detrusive. 

Strnj)S.—At  crown  and  at  the  sides  of  keyhole,  tensile;  at 
back  of  keyholes,  detrusive. 

Crt'6.— Transverse,  uniformly  loaded  along  its  length,  fixed  at 
both  ends. 

Xe?/.— With  single  gib,  transverse,  uniformly  loaded  along 
its  length,  fixed  at  both  ends. 

Key. — With  double  gib,  transverse,  uniformly  loaded  along 
its  length,  fixed  at  both  ends. 


140  STRENGTH   OP   MATERIALS. 


Woods. 


"When  a  beam  or  any  piece  of  wood  is  let  in  (not  mortised)  at 
an  inclination  to  another  piece,  so  that  the  thrust  will  bear  in 
the  direction  of  the  fibres  of  the  beam  that  is  cut,  the  depth  of 
the  cut  at  right  angles  to  the  fibres  shoiild  not  be  more  than  .2 
pf  the  ijiece,  the  fibres  of  which,  by  their  cohesion,  resist  the 
thrust. 


Shafts  and  Gudgeons. 

Shafts  are  divided  into  shafts  and  spindles,  according  to 
their  magnitude. 

-4  Gudgeon  is  the  metal  journal  cr  arbor  upon  which  a 
wooden  shaft  revolves. 

Shafts  are  siibjected  to  torsion  and  lateral  stress  combined,  or 
to  lateral  stress  alone. 

Lateral  Sti^'ncss  and  Sf/vj/f/f/i.-Shafts  of  equal  length 
h.ave  lateral  stiffness  as  their  breadth  and  the  cube  of  their  depth, 
and  have  lateral  strength  as  their  brcailth  and  the  square  of  their 
depths.  Hence,  in  shafts  of  ecpial  lengths,  their  stiffness  by  any 
increase  of  depth  increases  in  a  greatir  jiroportion  than  theii 
strength. 

Shafts  of  different  lengths  have  lateral  stiffness,  directly  as 
their  breadth  and  the  cube  of  their  depth,  and  inversely  as  the 
cube  of  their  length  ;  and  have  lateral  strength  directly  as  their 
breadth  and  as  the  square  of  their  depth,  and  inversely  as  their 
length.  Hence,  in  shafts  of  different  lengths,  their  stiffness  by 
any  increase  of  their  length  decreases  in  a  greater  proportion 
than  their  strength. 

Hollow  .shafts  having  uqual  lengths  and  equal  quantities  of 
material,  have  lateral  stiffness  as  the  scpiare  of  their  diiuneter, 
and  have  lateral  strength  as  their  diameters.  Hence,  in  hollow 
shafts,  one  having  twice  the  diameter  of  another  will  have  four 
times  the  stiffness,  and  but  double  tlie  str(>ngth ;  and  when  having 
equal  lengths,  by  an  increase  in  diameter  they  increase  in  stiff- 
ness in  a  greater  proportion  than  in  strength. 

The  stress  upon  a  shaft  from  a  weight  upon  it  is  jiroportioiial 
to  the  product  of  the  parts  of  the  shaft  multiplied  into  I'ach  other. 
Thus,  if  a  shaft  is  10  feet  in  length,  and  a  weight  ui>on  the  centro 
of  gravity  of  the  stress  is  at  a  point  2  feet  from  one  end,  the  parts 
2  and  8,  multiplied  together,  are  equal  to  16;  but  if  the  weight 
or  stress  were  ai)piied  in  the  middle  of  the  shaft,  the  parts  5  an  1 
&,  multiplied  together,  would  produce  2"i. 

The  ends  of  a  sliaft  having  to  sni)])()rt  the  whole  weight,  tho 
end  which  is  nearest  the  weight  lias  to  su])])ort  the  greatest  ])ro- 
portion  of  it,  in  the  inverse  projjortion  of  the  distance  of  tho 
weight  from  the  end.  Ibnce,  when  a  shaft  is  loaded  in  the 
middle,  each  of  the  journals  or  gudgeons  has  half  the  weight  or 

HtreKS  to  SUp])()rt. 

When  the  ion  I  upon  a  shaft  in  uniformlv  distributed  over  any 
imrt  of  it,  it  is  cousidered  an  united  in  tlie  middle  of  that  part; 


WOOD,   TIMBER,   ETC.  141 

and  if  the  load  is  not  tmiformly  distributed,  it  is  considered  as 
united  at  its  centre  of  gravity. 

When  the  transverse  section  of  a  shaft  is  a  regular  figure,  as  a 
square,  circle,  etc.,  and  the  load  is  applied  in  one  point^  in  order 
to  give  it  equal  resistance  throughout  its  length,  the  curve  of  the 
sides  becomes  a  cubic  parabola;  but  when  the  load  is  uniformly 
distributed  over  the  shaft,  the  curve  of  the  sides  becomes  a  semi- 
cubical  parabola. 

The  deflection  of  a  shaft  produced  by  a  load  which  is  uniformly 
distributed  over  its  length  is  the  same  as  when  five-eighths  of  the 
load  is  applied  at  the  middle  of  its  length. 

The  resistance  of  the  body  of  a  shaft  to  lateral  stress  is  as  its 
breadth  and  the  square  of  its  depth;  hence  the  diameter  will  be 
as  the  product  of  the  length  of  it  and  the  length  of  it  on  one  side 
of  a  given  point,  less  the  square  of  that  length. 


WOOD,  TIMBER,  ETC. 


Selection  of  Standing  Trees.— Wood  grown  in  a  moist 
soil  is  lighter  and  decaj's  sooner  than  that  grown  in  dry,  sandy 
soil. 

The  best  timber  is  that  grown  in  a  dark  soil  intermixed  with 
gravel.  Poplar,  cypress,  willow,  and  all  others  which  grow  best 
in  a  wet  soil,  are  exceptions. 

The  hardest  and  densest  woods,  and  the  least  subject  to  decaj', 
grow  in  warm  climates,  but  they  are  more  liable  to  split  and 
warp  in  seasoning. 

Trees  grown  upon  plains  or  in  the  centre  of  forests  are  less 
dense  than  those  from  the  edge  of  a  forest,  from  the  side  of  a 
hill,  or  from  open  ground. 

Trees  (in  the  U.  S. )  should  be  selected  in  the  latter  part  of 
Jiily  or  first  part  of  August;  for  at  this  seasor  the  leaves  of  the 
sound,  healthy  trees  are  fresh  and  green,  while  those  of  the  un- 
sound are  beginning  to  turn  yellow.  A  sound,  healthy  tree  is 
recognized  by  its  top  branches  being  well  leaved,  the  bark  even 
and  of  a  uniform  color.  A  rounded  top,  few  leaves,  some  of  them 
turned  yellow,  a  rougher  bark  than  common,  covered  with  para- 
sitic plants  and  with  streaks  or  spots  upon  it,  indicate  a  tree 
upon  the  decline.  The  decay  of  branches  and  the  separation  of 
bark  from  the  wood  are  infallible  indications  that  the  wood  is 
impaired. 

Fellinq  Timber, — The  most  suitable  time  for  felling  timber 
is  in  midwinter  and  in  midsummer.  Recent  experiments  indi- 
cate the  latter  season  and  in  the  month  of  July. 


142  WOOD,   TIMBER,   ETC. 

A  tree  should  be  allowed  to  attaia  full  maturity  before  being 
felled.  Oak  matures  at  75  to  100  years  and  upward,  according  to 
circumstances.  The  age  and  rate  of  growth  of  a  tree  are  indi- 
cated by  the  number  and  width  of  the  rings  of  annual  increase 
which  are  exhibited  in  a  cross-section. 

A  tree  should  be  cut  as  near  to  the  ground  as  practicable,  as 
the  lower  part  furnishes  the  best  timber. 

r>ressut(/  Thiibev. — As  soon  as  a  tree  is  felled,  it  .should  be 
stripped  of  its  bark,  raised  from  the  ground,  the  sap-wood  taken 
oflF,  and  the  timber  reduced  to  its  required  dim  nsions 

Inspection  of  Timber.— T\\e  qua  ity  of  wood  is  in  sorne 
degree  indicated  by  its  color,  which  should  be  nearly  uniform  in 
the  heart,  a  little  deeper  toward  the  centre,  and  free  from  sudden 
transitions  of  color.  White  spots  indicate  decay,  'i'he  sap-wood 
is  known  by  its  white  color;  it  is  next  to  the  bark,  and  very  soon 
rots. 

Defects  of  Titnher, — Wind-shakes  are  circular  cracks  sep- 
arating the  concentric  layers  of  wood  from  each  other.  It  is  a 
serious  defect. 

Splits,  cJieelis,  and  craefcs,  extending  toward  the  centre, 
if  deep  and  strongly  marked,  render  the  timber  unfit  for  use, 
unless  the  purpose  for  which  it  is  intended  will  admit  of  its 
being  split  through  them. 

JBrdsh-ivood  is  generally  consequent  upon  the  decline  of 
the  tree  from  age.  The  wood  is  porous,  of  a  reddish  color,  and 
breaks  short,  without  splintti-s. 

liolted  timber  is  that  which  has  been  killed  before  being 
felled,  or  which  has  died  from  other  causes.     It  is  objectionable. 

Knottfl  timber  is  that  containing  many  knots,  though 
sound;  usually  of  stunted  growth. 

Twisted  wood  is  when  the  grain  of  it  winds  spirally;  it  is 
unfit  for  long  pieces. 

Drtf-rot. — This  is  indicated  by  yellow  stains.  Elm  and 
beech  are  soon  afiected  if  left  with  the  bark  on. 

Lttrt/e  or  decayed  hiiots  injuriously  affect  the  strength  of 
timber. 


Seasoning  and  Preserving  Timber. 

Timber  freshly  cut  contains  about  37  to  4  >  per  cent,  of  liquids. 
]5y  exposure  to  the  air  in  seasoning  (me  year,  it  loses  from  17  to 
25  per  cent.,  and  when  seasoned  it  yet  retains  from  10  to  15  per 
cent. 

Timber  of  largo  dimensions  is  improved  and  rendered  less  lia- 
ble to  warp  and  crack  in  being  seasoned  by  immersion  in  water 
for  some  weeks 

Kor  the  purpose  of  s  asoning,  timber  should  1«'  juled  under 
shelter  and  kei)t  dry;  it  should  have  a  free  circulation  of  air 
about  it,  without  being  exposed  to  strong  currents.  The  boUom 
jiiece  should  be  pla<;('  1  Upon  skids,  which  should  b(!  free  from 
decay,  raised  nf)t  less  tlian  t'vo  f 'et  from  the;  ground;  a  space  of 
an  inch  shoul  I  intervene  bi-tween  the  pieces  of  the  same  liori- 


WOOD,   TIMBER,   ETC.     -  143 

zontal  layers,  and  slats  or  piling-strips  placed  between  cacli 
layer,  one  near  each  end  of  the  pile  and  others  at  short  distances. 
in  order  to  keep  the  timber  from  winding.  Tliese  strips  shoul  1 
be  one  over  the  other,  and  in  large  piles  should  not  be  less  than 
one  inch  thick.  Light  timber  may  be  piled  in  the  upper  portion 
of  the  shelter,  heavy  timber  upon  the  ground  floor.  Each  pile 
should  contain  biat  one  description  of  timber.  The  piles  should 
be  at  least  2.^  feet  apart. 

Timber  should  be  repiled  at  inter^-als,  and  all  pieces  indicat- 
ing decay  should  be  removed,  to  prevent  their  affecting  those 
■which  are  still  sound. 

1  imber  houses  are  best  provided  -with  blinds,  -which  keep  out 
rain  and  snow,  but  which  can  be  tiirned  to  admit  air  in  fine 
■weather,  and  they  should  bo  kept  entirely  free  from  any  pieces 
of  decayed  ■«'ood. 

The  gra  lual  mode  of  seasoning  is  the  most  favorable  to  the 
strength  and  durability  of  timber,  but  various  methods  have 
been  proiDosed  for  hastening  the  process.  For  this  purpose, 
steaming  timber  has  been  applied  ■with  success  ;  and  the  results 
of  experiments  of  various  processes  of  saturating  timber  M'ith  a 
solution  of  corrosive  sublimate  and  antiseptic  fluids  are  very 
satisfactory.  This  process  hardens  and  seasons  ■wood,  at  the 
same  time  that  it  secures  it  from  dry-rot  and  the  attacks  of 
■worms.  Kiln-drying  is  servicealle  only  for  boards  and  pieces 
of  small  dimensions,  and  is  apt  to  cause  cracks  and  to  impair  the 
strength  of  -vs'ood,  imless  performed  very  slowly.  Charring  or 
painting  is  highly  injiirious  to  any  but  seasoned  timber,  as  it 
effectually  prevents  the  drying  of  the  inner  part  of  the  wood,  in 
consequence  of  which  fermentation  and  decay  soon  take  place. 

Timber  piled  in  badly-ventilated  sheds  is  apt  to  be  attacked 
■with  the  common-rot.  The  first  outward  indications  are  yello^w 
spots  upon  the  ends  of  the  pieces,  and  a  yellowish  dust  in  the 
checks  and  cracks,  particularly  where  the  pieces  rest  upon  the 
piling-strips. 

Timber  requires  from  two  to  eight  years  to  be  seasoned  thor- 
oughly, according  to  its  dimensions.  It  should  be  worked  as 
soon  as  it  is  thoroughly  dry,  for  it  deteriorates  after  that  time. 

Oak  timber  loses  one-fifth  of  its  weight  in  seasoning,  and  about 
one-third  of  its  weight  in  becoming  perfectly  dn'.  Seasoning  is 
the  extraction  or  dissipation  of  the  vegetable  juices  and  moisture, 
or  the  solidification  of  the  albumen.  When  wood  is  exposed  to 
currents  of  air  at  a  high  temperature,  the  moisture  evaporates 
too  rapidly  and  the  wood  cracks;  and  when  the  teraperatiire  is 
high  and  sap  remains,  it  ferments,  and  dry-rot  ensues. 

Timber  is  subject  to  common-rot  or  dry-rot,  the  former  occa- 
sioned by  alternate  exposure  to  moisture  or  dryness.  The  prog- 
ress of  this  decay  is  from  the  exterior;  hence  the  covering  of  the 
surface  with  paint,  tar,  etc. ,  is  a  preservative. 

Painting  and  charring  green  timber  hastens  its  decay. 

Di'U  or  Sfip  rot  is  inherent  in  timber,  and  it  is  occasioned 
by  the  2-)utrefaction  of  the  vegetable  albumen.  Sap  wood  contains 
a  large  proportion  of  fermentable  elements.     Insects  attack  wood 


114  •     WOOD,   TIMBER,   ETC. 

for  the  sugar  or  gum  contained  in  it,  and  fungi  subsist  Tipon  the 
albumen  of  woocl;  hence,  to  arrest  dry-rot,  the  albumen  must  be 
either  extracted  or  solidified. 

In  the  seasoning  of  timber  naturally  there  is  required  a  period 
of  from  2  to  4  years.  Immersion  in  water  facilitates  seasoning 
by  solving  the  sap. 

The  most  effective  method  of  preserving  timber  is  that  of  ex- 
pelling or  exhausting  its  fluids,  solidifying  its  albumen,  and  in- 
troducing an  antiseptic  liquid. 

The  strength  of  impregnated  timber  is  not  reduced,  and  its  re- 
silience is  improved. 

In  desiccating  timber  by  expelling  its  fluids  by  heat  and  air, 
its  strength  is  increased  fully  15  per  cent. 

In  coating  unseasoned  timber  with  creosote,  tar,  etc.,  the 
fluiJs  are  retained,  and  decay  facilitated  thereby. 

When  timber  is  saturated  with  creosote,  tar,  antiseptics,  etc., 
it  is  ;.lso  preserved  from  the  attack  of  worms.  Jarrow  wood,  from 
Australia,  is  not  subjocted  to  their  attack. 

The  condition  of  timber,  as  to  its  soundness  or  decay,  is  readily 
recognized  when  struck  a  quick  blow. 

Timber  that  has  been  for  a  long  time  immersed  in  water,  when 
brought  into  the  air  and  dried,  becomes  brashy  and  useless. 

When  trees  are  barked  in  the  spring,  they  should  not  be  felled 
until  the  foliage  is  dead. 

Timber  cannot  be  seasoned  by  either  smoking  or  charring;  but 
when  it  is  to  be  used  in  locations  where  it  is  exposed  to  worms 
or  to  produce  fungi,  it  is  proper  to  smoke  or  char  it. 

Timber  may  be  partially  seasoned  by  being  boiled  or  steamed. 


Impregnation  of  Wood. 

The  several  processes  are  as  follows  : 

K}/(lit,  18:52.  Saturated  with  corrosive  sublimate.  Solution 
1  lit.  of  chloride  of  mercury  to  4  gallons  of  water. 

Jiuruf'tt,  1838.  Impregnation  with  chloride  of  zinc  by  sub- 
mitting the  wood  endwise  to  a  jirrssure  of  ]•")()  lbs.  per  sipiare 
iucli.     Solution  1  lb.  of  the  chloride  to  10  gallons  of  water. 

Jttnirhcri.  Impregnation  by  submitting  the  wood  endwise 
to  a  jtressure  of  about  ir>  lbs.  per  sijuare  inch.  Solution  1  lb.  of 
sulphate  of  copper  to  1'2\  gallons  of  water. 

Jiethel.  Impregnation  by  submitting  the  wood  endwise  to  a 
pressure  of  150  to  200  lbs.  jier  B(piare  inch,  with  oil  of  creosote 
mixed  witli  bituminous  mattiT. 

Louis  S.  liohhins,  IHi',.").  Atjueous  vapor  dissipated  by  the 
wood  Ixiiig  heated  in  a  chaiiilMT,  the  albumen  solidifiod,  then 
Kubinitti'd  to  the  vajxtr  of  coal  tar,  resin,  or  bituininons  oils, 
which,  being  at  a  temperature  not  less  than  325  ,  readily  takea 
th"  i>lace  of  tho  vajKJr  exjjelled  by  a  temi)erature  of  212'. 

Fluids  will  pass  with  the  grain  of  wood  with  great  fac^ility,  but 
will  not  enter  it  except  to  a  very  limited  extent  when  applied 
externally. 


WOOD,   TIMBER,    ETC. 


145 


Absorption  of  Preserving  Solution  by  different 

Woods  for  a  Period  of  Seven  Days. 

Average  Pounds  per  Cubic  Foot. 


Black  Oak 3  6 

Chestnut. ...... .3. 


Hemlock.. 
Ked  Oak. 


.2.6 
.3.9 


Rock  Oak 3.9 

White  Oak 3.1 


Proportion  of  Water  in  various  Woods. 


Alder  ( Beinla  alwis) 41.6 

Ash  {Frojeinus  excelsior). . .  .28.7 

Birch  (BeMa  alba) 30.8 

Elm  (  Ulmus  campestris)  ..  .4-1.5 
Horse-chestnut      {^^scuius 

hippncasi) ....     38.2 

Larch  :Pinus  lari.i) 48.6 

Mountain  Ash  {Sorbusaucu- 

paria) 2^.3 

Oak  ( (^uercus  roburi 34. 7 


Pine  {Pinus  Sylvestns  i.).  .39.7 
Red  Beech  ( Fagiis  sylvaiica).  39. 7 
Red  Pine  (Pinus  picea  durj. 45.2 
Sycamore  {Acer  pseudo plat- 
anus  )   27. 

White  Oak  {Quercus  aftff).  .36  2 
White    Pine    (Pinus    abies 

dur) -M.l 

White  FoY)]a.v[Populus  alba).5i).6 
Willow  { Salix  aiprea) 26. 


Ash.. 
Beech 
Cedar 


.1. 


.86 
.66 


Comparative  EesUience  of  Timber. 

Chestnut  .  .73  I  Larch    ...   .84 

Elm 54     Oak 63 

Fir 4      Pitch  Pine  .57 


Spruce  ...  .64 

Teak 59 

Yel.  Pine.  .64 


Weight  and  Strength  of  Oak  and  Yellow  Pine. 


White  O4S,  Va. 

Yellow  Pine,  Va. 

Live  Oak. 

Age. 

Round. 

Square. 

Round. 

Square. 

Green   

1  Year 

64.7 
53.6 
46. 

67.7 
53  5 
49.9 

47.8 
39.8 
34.3 

39.2 
34.2 
33.5 

78.7 

2  Years 

66.7 

In  England,  timber  sawed  into  boards  is  classed  as  follows: 

6|  to  7  ins.  in  width,  Battens;  81  to  10  ins.,  Deals;  and  11  to 
12  ins.,  Planks. 

In  a  perfectly  dry  atmosphere  the  durability  of  woods  is  almost 
unlimited.  Rafters  of  roofs  are  known  to  have  existe.i  1,000 
years,  and  piles  submerged  in  fresh  water  have  been  found  per- 
fectly sound  800  years  from  the  period  of  their  being  driven. 

DistUUltion,. — From  a  single  cord  of  pitch  pine  distilled  by 
chemical  apparatus,  the  following  substances  and  in  the  quanti- 
ties stated  have  been  obtained  : 


Charcoal 50  bushels. 

Illum'ng  Gas  .ab't  1000  cu.  ft. 
Illum'ng  Oil  and  Tar. 50  galls. 
Pitch  or  Resin \\  barrels. 

7 


Pyroligenous  Acid.  .100  galls. 
Sp'ts  of  Turpentine     20     " 

Tar  1  barrel. 

Wood  Spirit 5  gallons. 


146  WOOD,   TIMBER,   ETC. 

Decrease  in  Dimensions  of  Tiniber  by  Seasoning. 

Woods.                                                 Ins.  Ins. 

Cedar,  Canada 14     to  13] 

Elm 11      to  1U5 

Oak,  English 12      to  llf 

Pitch  Pine,  North 10  X  10  to  O^  X  9| 

Pitch  Pine,  South 18^    to  lb] 

Spruce   «!    to  8^ 

"White  Pine,  American 12      to  11^ 

Yellow  Pine,  North  18      to  17| 


The  weight  of  a  beam  of  English  oak,  when  wet,  was  reduced 
by  seasoning  from  972.25  to  030.5  pounds. 


REVOLVING  DISK. 
To   compute   the   Power. 

Etjle. — Multiply  one  half-the  weight  of  the  disk  by  the  height 
due  to  the  velocity  of  its  circumference  in  feet  per  second. 

Example.— A  grindstone  3}  feet  in  diameter,  weighing  2,000 
lbs.,  is  required  to  make  362|  rcsvolutions  per  minute  ;  what 
power  must  be  communicated  to  it? 

Circum.  of  3 1  =  10.6  feet,  which  X  3(52. 25 -f- GO  =  04  feet  per 
second.     Then  2,000-^  2  X  r.4  =  64,000  lbs.  raised  1  foot. 

Note.— If  the  revolving  disk  is  not  an  entire  or  solid  wheel, 
being  a  ring  orannulus,  it  must  fir.st  be  computed  as  if  an  entire 
disk,  and  then  the  portion  wanting  must  be  computed  and  de- 
ducted. 

Power  concentrated  in  Moving   Bodies. 

Simple  power  is  force  multiplied  by  its  velocity  Power  con- 
centrated in  a  moving  body  is  the  weight  of  the  b'ody  multiplied 
by  the  square  of  its  velocity;  and  the  product  divided  by  the 
accclleratrix,  or  the  powcir  concentrat<Hl  in  a  moving  body,  is 
equal  to  the  power  expended  in  generating  the  motion. 


SHRINKAGE  OF   CASTINGS. 

Iron,  small  cylinders —  I.IC  inch  per  foot. 

"      1'>P«'«     rr-A-H    inch  per  foot. 

"      Girders,  beams,  etc =:^  l-H  in  !">  inches. 

"      Large  cylinders,  the  contraction  of )        ,  ,-  ,     . 

diameter  ut  t..i..         \  =  1-16  per  foot. 

"  bottom    ..  :^M2  per  foot. 

"  "  ccmtraction  in  length  —  1-8  in  16  inches. 

Brass,  thin ^  j.H  j„  .,  i,„.i,os. 

Brass,  thick —  1-S  in  10  in.-.hes. 

^"""      • —  5-16  in  11  foot. 

L'''"l 5-1 6  in  11  foot. 

^'"I»I"r 3-16  in  a  foot. 

l^»»'""tli   -:^  5-32  in  a  foot. 


WHEEL   GEARING.  147 

WHEEL  G-EARING-. 


The  pitch  line  of  a  wheel,  is  the  circle  upon  which  the  pitch 
is  measured,  and  it  is  the  circumference  by  which  the  diameter, 
or  the  velocity  of  the  wheel,  is  measured. 

The  pitch,  is  the  arc  of  the  circle  of  the  pitch  line,  and  is  de- 
termined by  the  number  of  the  teeth  in  the  wheel. 

The  true  pitch  i^chordial;,  or  that  by  which  the  dimensions  of 
the  tooth  of  a  wheel  are  alone  determined,  is  a  straight  line 
drawn  from  the  centres  of  two  contiguous  teeth  upon  the  pitch 
line. 

The  line  of  centres,  is  the  line  between  the  centres  of  two 
wheels. 

The  radius  of  a  wheel,  is  the  semi-diameter  running  to  the 
periphery  of  a  tooth.  The  pitch  radivis,  is  the  semi-diameter 
running  to  the  pitch  line. 

The  length  of  a  tooth,  is  the  distance  from  its  base  to  its  ex- 
tremity. 

The  breadth  of  a  tooth,  is  the  length  of  the  face  of  wheel. 

The  teeth  of  wheels  should  be  as  small  and  numerous  as  is 
consistent  with  strength. 

When  a  pinion  is  driven  by  a  wheel,  the  number  of  teeth  in 
the  pinion  should  not  be  less  than  eight. 

When  a  wheel  is  driven  by  a  pinion,  the  number  of  teeth  in 
the  pinion  should  not  be  less  than  ten. 

The  number  of  teeth  in  a  wheel  shotild  always  be  prime  to  the 
number  of  the  pinion;  that  is,  the  number  of  teeth  in  the  wheel 
should  not  be  divisible  by  the  number  of  teeth  in  the  pinion 
without  a  remainder.  This  is  in  order  to  prevent  the  same  teeth 
coming  together  so  often  as  to  cause  an  irregular  wear  of  their 
faces.  An  odd  tooth  introduced  into  a  wheel  is  termed  a  hunt- 
ing tooth  or  cog. 

To  compute  the  Pitch  of  a  Wheel. 

KuLE. — Divide  circumference  at  the  pitch-line  by  the  number 
of  teeth. 

Example. — A  wheel  40   ins.   in  diameter  requires  75  teeth  ; 

what  is  its  pitch  ? 

3.1416X40      ,^„,  . 
^g =  1.6755  ins. 


To  compute  the  Chordial  Pitch. 

KuLE.— Divide  180°  by  the  number  of  teeth,  ascertain  the  sine 
of  the  quotient,  and  multiply  it  by  the  diameter  of  the  wheel. 

Example. — The  number  of  teeth  is  75,  and  the  diameter  40 
inches;  what  is  the  true  pitch  ? 

180  ^  2°  24'  and  sin.  of  T  24'  =  .04188,  which  X  40  =  1.6752  ins. 
75 


148  WHEEL   GEARING. 

To  compute  the  Diameter  of  a  "Wheel. 

RuiiE. — Multiply  the  number  of  teeth  by  the  pitch,  and  divide 
the  ijroduct  by  3.1416. 

Example.  — The  number  of  teeth  in  a  wheel  is  75,  and  the  pitch 
1.075  ins. ;  what  is  the  diameter  of  it? 

11X1:615^40  ins. 
3.1416 


To  compute  the  Number  of  Teeth  in  a  Wheel. 

liuLE. — Divide  the  circumference  by  the  pitch. 


To   compute  the  Diameter  when  the  True  Pitch  is 

given. 

Rule. — Multiply  the  number  of  teeth  in  the  wheel  by  the  true 
pitch,  and  again  by  .3184. 

Example.  — Take  the  elements  of  the  preceding  case. 

75  X  1.6752  X  .3184  =  40  ins. 


To  compute  the  Number  of  Teeth  in  a  Pinion  or 
Follower  to  have  a  given  Velocity. 

Rule. — Multiply  the  velocity  of  the  driver  by  its  number  of 
teeth,  and  divide  the  product  by  the  velocity  of  the  driven. 

Example. — The  velocity  of  a  driver  is  IG  revolutions,  the 
number  of  its  teeth  54,  and  the  velocity  of  the  pinion  is  48;  what 
is  the  number  of  its  teeth  ? 

liX^i=.  18  teeth. 

48 

2.  A  wheel  having  75  teeth  is  making  IG  revolutions  per 
minute;  what  is  the  number  of  teeth  reijuircd  in  the  pinion  to 
make  24  revolutions  iu  the  same  time  ? 

10  X  75 


24 


=  50  t«eth. 


To  compute  the  Proportional  Radius  of  a  Wheel 

or  Pinion. 

Rti.K.  Miilti]ily  the  length  of  tlie  line  of  erntris  by  the  num- 
Ikt  dT  ti'i'tli  in  tlie  wheel  for  the  wheel,  and  ill  tlie  pinion  for  the 
j>iiiiiin,  and  divide  by  the  number  of  tooth  m  both  the  wheel  ond 
piiiiuu. 


WHEEL  GEARING.  149 

To  compute  the  Diameter  of  a  Pinion,  when  the 
Diameter  of  the  Wheel  and.  Number  of  Teeth  in 
the  "Wheel  and  Pinion  are  given. 

KuLE. —Multiply  the  diameter  of  the  wheel  by  the  number  of 
teeth  in  the  pinion,  and  divide  the  product  by  the  number  of 
teeth  in  the  wheel. 

Example. — The  diameter  of  a  wheel  is  25  inche-s,  the  number 
of  its  teeth  210,  and  the  niimber  of  teeth  in  the  pinion  30;  what 
is  the  diameter  of  the  pinion? 
25X30 


210 


;  3. 57  ins. 


To  compute  the  Circumference  of  a  Wheel. 

KuLE. — Multiply  the  number  of  teeth  by  their  pitch. 


To  compute  the  Revolutions  of  a  Wheel  or  Pinion. 

KuLZ. — Multiply  the  diameter  or  circumference  of  the  wheel 
or  the  number  of  its  teeth,  as  the  case  may  be,  by  the  number  of 
its  revolutions,  and  divide  the  product  by  the  diameter,  circum- 
ference, or  number  of  teeth  in  the  pinion. 

Example. — A  pinion  10  inches  in  diameter  is  driven  by  a  wheel 
2  feet  in  diameter,  making  46  revolutions  per  minute;  what  is  the 
number  of  revolutions  of  the  pinion  ? 

^  ^  ^^^^  ^^  =  110.4  revolutions. 


To  compute  the  Velocity  of  a  Pinion. 

KuLE. — Divide  the  diameter,  circumference,  or  number  of 
teeth  in  the  driver,  as  the  case  may  be,  by  the  diameter,  etc.,  of 
the  pinion. 

When  there  is  a  Series  or  Train  of  Wheels  and  Pinions. 
Rule.  —  Divide  the  continued  product  of  the  diameter,  circum- 
ference, or  number  of  teeth  in  the  wheels  by  the  continued  pro- 
duct of  the  diameter,  etc.,  of  the  pinions. 

Example. — If  a  wheel  of  32  teeth  drive  a  pinion  of  10,  upon 
the  axis  of  which  there  is  one  of  30  teeth,  driving  a  pinion  of  8, 
what  are  the  revolutions  of  the  last? 

32      30      9G0      ,„         ,   ,. 

ro-^-8^8o=^2"'^°^^*^°^'- 

Ex.  2. — The  diameters  of  a  train  of  wheels  are  6,  9,  9,  10,  and 
12  inches;  of  the  pinions,  6,  G,  6,  6,  and  6  inches;  and  the  num- 


150  WHEEL   GEARING. 

ber  of  revolutions  of  tlie  driving  shaft  or  prime  mover  is  10; 
what  are  the  revolutions  of  the  last  pinion? 

GX9X9XlOXi2XU)^5^^.-  .evolutions. 
GX6X6X6X6  777b 


To  compute   the  Proportion  that  the  Velocities  of 
the  Wheels  in  a  Train  should  bear  to  one  another. 

Rule.— Subtract  the  less  velocity  from  the  greater,  and  divide 
the  remainder  by  one  less  than  the  number  of  wheels  in  the 
train  ;  the  quotient  is  the  number,  rising  in  arithmetical  pro- 
gression from  the  less  to  the  greater  velocity. 

Example.— What  should  be  the  velocities  of  3  wheels  to  pro- 
duce 18  revolutions,  the  driver  making  3  ? 
18  —  3=:::15__.y5__  number  to  be  added  to  velocity  of  the  driver 

=^7.5  4-3  =  10.5,  and   10.5  +  7.5  =  18  revolutions. 
Hence  3,  10.5,  and  18  are  the  velocities  of  the  three  wheels. 


General  Illustrations. 

1.  A  wheel  96  inches  in  dianicter,  having  42  revolutions  per 
minute,  is  to  drive  a  shaft  75  revolutions  per  minute;  what 
should  be  the  diameter  of  the  pinion  V 

^Xi^  =  53.7Gins. 
75 

2.  If  a  pinion  is  to  make  20  revolutions  per  minute,  reqiiired 
the  diameter  of  another  to  make  58  revolutions  in  the  same  time. 

58 -^20  =  2.9  =  the  ratio  of  their  diameters.  Hence,  if  one 
to  make  20  revolutions  is  given  a  diameter  of  30  inches,  the 
other  will  be  30  -^  2.9  =  10. 345  ins. 

3.  Re(iuired  tlie  diameter  of  a  pinion  to  make  12^,  revolutions 
in  the  same  time  as  one  of  32  ins.  diameter  making  20. 

32  X  2G  _  p^p^  r,p.  ing 
12.5 

4.  A  shaft,  having  22  revolutions  per  minute,  is  to  drive  an- 
other shaft  at  tlio  rate  of  15,  the  distance  bctw.'on  the  two  shafts 
up(m  tlie  line  of  ccntriis  is  45  inches;  what  should  be  the  diame- 
ter of  the  wheels? 

Then,  Ist,  22-1-15  :  22:  :  45  :  20.75  =  inches    in    the   radius  of 

the  pinion. 

2d.  22  f- 15  :  15  :  :  4'.  :  18.24    -  inches  in  the  radius  of  the  spur. 

5.  A  driving  shaft,  having  10  revolutions  ]ter  minute,  is  to 
drive  a  shaft  81  revolutions  i)er  minute,  the  motion  to  be  com- 
mnnic;ited  by  two  geand  whe.ls  and  two  jjulleys,  with  an  int('r- 
niediate  sliaft;  th<^  driving  wheel  is  to  contain  51  teeth,  and  the 
driving  i)iilley  upon  the  driven  shaft  is  to  be  2'>  inches  in  diam- 
eter; n-.iuired  the  number  of  teeth  in  the  driven  wheel,  and  the 
diameter  of  the  driven  pulley. 


WHEEL   GEARING.  151 


Let  the  driven  wheel  have  a  velocity  of  y  Ui  x  81  ==  36,  a  mean 
proportional  between  the  extreme  velocities  16  and  81. 
Then,  1st.   36  :  16  :  :  54  :  21  =  teeth  in  the  driven  wheel. 
2d.  81  :  36  :  :  25  :  11. 11  =  inches  diameter  of  the  driven  pulley. 

6.  If,  as  in  the  i^receding  case,  the  whole  number  of  revolu- 
tions of  the  driving  shaft,  the  number  of  teeth  in  its  wheel,  and 
the  diameters  of  the  pulleys  are  given,  what  are  the  revolutions 
of  the  shafts  ?     Then, 

1st.  18  :  16  :  :  54  :  48  =  revolutions  of  the  intermediate  shaft. 

2d.  15  :  48  :  :  25  :  80  =;  revolutions  of  the  driven  shaft. 


To  compute  the  Diameter  of  a  Wheel  for  a  given , 
Pitch  and  Number  of  Teeth. 

KuiiE.  — Miiltiply  the  diameter  in  the  following  table  for  the 
number  of  teeth  by  the  pitch,  and  the  product  will  give  the  di- 
ameter at  the  pitch  circle. 

Example.  — What  is  the  diameter  of  a  wheel  to  contain  48  teeth 
of  2.5  ins.  J) itch? 

15.29X2.5  =  38.225  ins. 


To  compute  the  Pitch  of  a  Wheel  for  a  given  Di- 
ameter and  Number  of  Teeth. 

Rule.  —Divide  the  diameter  of  the  wheel  by  the  diameter  in 
the  table  for  the  number  of  teeth,  and  the  quotient  will  give  the 
pitch. 

Example. — Wha.t  is  the  pitch  of  a  wheel  when  the  diameter  of 

it  is  50  94  inches,  and  the  number  of  its  teeth  80  ? 

50  94      -  . 

=  2  ms. 

25.47 


To  compute  the  Stress  that  may  be  borne  by  a  Tooth. 

liULE. — Multiply  the  value  of  the  material  of  the  tooth  to  resist 
a  transverse  strain,  as  estimated  for  this  character  of  stress,  by 
the  breadth  and  square  of  its  depth,  and  divide  the  product  by 
the  extreme  length  of  it  in  the  decimal  of  a  foot. 


To  compute  the  Number  of  Teeth  of  a  Wheel  for 
a  given  Diameter  a''d  Pitch. 

RtTLE. — Divide  the  diameter  by  the  pitch,  and  o   posite  to  the 
quotient  in  the  following  table  is  given  the  number  of  teeth. 


152 


WnEEL   GEARING. 


Pitch  of  Wheels. 

A  Table  "W'Herebt  to  Compute  the  Diameter  op  a  Wheeij  fob  a 
GIVEN  Pitch,  or  the  Pitch  for  a  gxaen  Diameter. 

From  8  to  192  teeth. 


No.  of 

Diame- 

No. of 

Diame- 

No. of 

Diame- 

No. of 

Diame- 

No. of 

Diame- 

Teeth 

ter. 

Teeth. 

45 

ter. 

Teetli. 

ter. 

Teeth. 

ter. 

Teeth . 

156 

ter. 

8 

2.61 

14.33 

82 

26.11 

119 

37.88 

49.66 

9 

2  93 

46 

14.65 

83 

26.43 

120 

38.2 

157 

49.98 

< 

3.24 

47 

14.97 

84 

26.74 

121 

38.52 

158 

50.3 

3.55 

48 

15.29 

85 

27.06 

122 

38.84 

159 

50.61 

12 

3.86 

49 

15.61 

86 

27.38 

123 

39.16 

160 

50.93 

13 

4.18 

50 

15.93 

87 

27.7 

124 

39.47 

161 

51.25 

U 

4.49 

51 

16.24 

88 

28.02 

125 

39.79 

162 

51.57 

15 

4.81 

52 

16.56 

89 

28.33 

126 

40.11 

163 

51.89 

16 

5.12 

53 

16.88 

90 

28.05 

127 

40.43 

164 

52.21 

17 

5.44 

54 

17.2 

91 

28.97 

128 

40.75 

165 

52.52 

18 

5.76 

55 

17  52 

92 

29.29 

129 

41.07 

166 

52.84 

19 

6.07 

56 

17.8 

93 

29.01 

130 

41.38 

167 

53.16 

20 

6.39 

57 

18.15 

94 

29.93 

131 

41.7 

168 

53.48 

21 

6.71 

58 

18.47 

95 

30.24 

132 

42.02 

169 

53.8 

22 

7.03 

59 

18.79 

90 

30.56 

133 

42.34 

170 

54.12 

23 

7.31 

60 

19.11 

97 

30  88 

134 

42,66 

171 

54.43 

24 

7.66 

61 

19.42 

98 

31.2 

135 

42.98 

172 

54.75 

25 

7.98 

62 

19.74 

99 

31.52 

136 

43.29 

173 

55.07 

26 

K3 

63 

20.06 

100 

31.84 

137 

43.61 

174 

55.39 

27 

8  61 

64 

20.38 

101 

32.15 

138 

4.3.93 

175 

55.71 

28 

8.93 

05 

20.7 

102 

32.47 

139 

44.25 

176 

56.02 

29 

9.25 

66 

21.02 

103 

32.79 

140 

44.57 

177 

56.34 

30 

9.57 

67 

21.33 

104 

33.11 

141 

44.88 

178 

56.66 

31 

9.88 

08 

21.05 

105 

33.43 

142 

4.5.2 

179 

56.98 

32 

10.2 

!  69 

21.97 

106 

33.74 

143 

45.52 

180 

57.23 

33 

10.52 

70 

22.29 

107 

34.00 

144 

45.84 

181 

57.62 

34 

10.84 

71 

22.61 

108 

34.38 

145 

46.16 

182 

57.93 

35 

11.16 

72 

22.92 

1(9 

34.7 

146 

46.48 

183 

58.25 

36 

11.47 

73 

23.24 

110 

35.02 

147 

46.79 

184 

58.57 

37 

11.79 

74 

23.56 

111 

35.34 

148 

47.11 

185 

.58.89 

3H 

12.11 

75 

23.88 

112 

35.65 

149 

47.43 

186 

59.21 

39 

12.43 

76 

24.2 

113 

35  97 

150 

47.75 

187 

59.53 

■10 

12.71 

77 

24.52 

114 

36.29 

151 

48.07  1 

188 

59.84 

•11 

1.3.(16 

78 

24.83 

115 

36.61 

1.52 

48  39 

189 

00.16 

■12 

13.38 

79 

25.15 

110 

36.93 

1.53 

48.7 

190 

60.48 

43 

l.i  7 

HO 

2  "..47 

117 

37.25 

154 

49.02 

191 

60.81 

41 

14.02 

i  81 

2.5.79 

118 

37.56 

155 

49.34  ! 

192 

61.13 

WHEEL    GEARING. 


153 


Teeth  of  Wlieels, 

EpiCTCLOIDAIi. 

In  order  tliat  the  teeth  of  the  wheels  and  pinions  should  work 
evenly  and  without  unnecessary  rubbing  friction,  the  face  (from 
pitch  line  to  top)  of  the  outline  should  be  determined  by  an 
epicycloidal  curve,  and  the  flank  (from  pitch  line  to  base)  by  an 
hypocj'cloidal. 

When  the  generating  circle  is  equal  to  half  the  diameter  of  the 
pitch  circle,  the  hypocycloid  described  by  it  is  a  straight  diamet- 
rical line,  and,  consequently,  the  outline  of  a  flank  is  a  right  line 
and  radial  to  the  centre  of  the  wheel. 

If  a  like  generating  circle  is  used  to  describe  face  of  a  tooth  of 
other  wheel  or  i^inion  respectively,  the  wheel  and  pinion  will 
operate  evenly. 

Im'OLUTE. 

Teeth  of  two  wheels  will  work  trulj'  together  when  surfaces  of 
their  face  is  an  involute  ;  and  that  tv.o  such  wheels  should  work 
truly,  the  circles  from  which  the  involute  lines  for  each  wheel 
are  generated  must  be  concemr-ic  with  the  wheels,  with  diameters 
in  the  same  ratio  as  those  of  th&  wheels. 

Curves  of"  Teeth.— In  the  pattern  shop,  the  curves  of  epi- 
cycloidal or  involute  teeth  are  defined  by  rolling  a  template  of 
the  generating  circle  on  a  template  corresponding  to  the  pitch 
line.  A  scriber  on  the  periphery  of  the  template  being  used  to 
define  the  ciarve. 

Least  number  of  teeth  that  can  be  employed  in  j^inions  having 
teeth  of  following  classes  are  :  involute,  25  ;  epicycloidal,  12  ; 
staves  or  pins,  6. 


Construction  of  Gearing. 
Kthe  dimensions  of  two  wheels  are  determined,  as  well  as  the 
size  of  the  teeth  and  spaces,  the  wheel  is  drawn  as  is  .shown  in 
figure.     The  starting-point   for  the   division  of  the  wheels   is 
Where    the  two 

pitch  -circles  )••,  ,-'       /       x—^ 

meet  in  A.  It  ,  .  ^' 
is  advisable  to  \^ 
determine  the 
exact  diameters 
of  the  wheels  by 
calculation,  if 
the  difference 
between  them  is 
remarkable;  for 
any  division 
upon  two  circles 
of  unequal  size, 

t 


154 


WHEKL   GEARING. 


by  meaBS  of  a  divider,  is  incorrect,  because  the  latter  measures 
the  chord  instead  of  the  arc.  From  the  point  A  we  construct  the 
epicycloid  C,  by  rolling  the  circle  A  upon  B,  as  its  base  line. 
That  short  piece  of  the  epicycloid,  from  the  pitch-line  to  the  face 
of  the  tooth,  is  the  curvature  for  that  part  of  the  tooth  and  the 
wheel  B.  This  curvature  obtained  for  one  side  of  the  tooth, 
serves  for  both  sides  of  it,  and  also  for  all  the  teeth  in  the  wheel. 
The  lower  part  of  the  tooth,  or  that  inside  the  pitch-line,  is  im- 
material to  the  working  of  the  wheel;  this  may  be  a  straight  line, 
as  shown  by  the  dotted  lines  which  are  in  the  direction  of  the 
diameters,  or  may  be  a  curved  line,  as  is  seen  in  the  wheel  A. 
This  line  must  be  so  formed  as  not  to  touch  the  upper  or  curved 
part  of  the  tooth.  T  he  root  of  the  tooth,  or  that  part  of  it  which 
is  connected  with  the  rim  of  the  wheel,  is  the  weakest  part  of 
the  tooth,  and  may  be  strengthened  by  filling  the  angles  at  the 
corners.  The  curvature  for  the  teeth  in  the  wheel  A  is  found  in  a 
similar  manner  to  that  for  B.  The  pitch-circle  A  serves  now  as 
a  base-line,  and  the  circle  B  is  rollctl  upon  it,  to  obtain  the 
circle  I).  This  line  forms  the  curvature  for  the  teeth  of  A,  and 
serves  for  all  tlie  teeth  in  A— also  for  both  sides  of  the  teeth.  In 
most  practical  cases  the  curvature  of  the  teeth  is  described  as  a 
part  of  a  circle,  drawn  from  the  centre  of  the  next  tooth,  or 
fi"om  a  pt)int  more  or  less  above  or  bt'low  that  centre,  or  the 
radius  greater  or  les-s  in  length  than  the  pitch  of  the  wheel. 
Such  circles  are  never  correct  curves,  and  no  rule  can  be  estab- 
lished by  which  their  size  ami  centre  meets  the  form  of  the  epi- 
cycloid. 


Bevel  Wheels, 


lii  If  the  linos  C  A 
and  B  C  represent 
the  prolonged  axes, 
which  are  to  revolve 
withdifferentorsim- 
ilar  velocities,  the 
position  and  sizes 
of  the  wheels  for 
driving  these  axes 
are  determined  by 
the  distance  of  the 
wheels  from  the 
point  C.     The  di- 


WHEEL   GEARING. 


155 


ameters  of  the  wheels  are  as  the  angles  a  and  (5,  and  inversely  as 
the  number  of  revolutions.  These  angles  are  therefore  to  be  de- 
termined before  the  wheels  can  be  drawn.  By  measuring  the 
distances  from  C  to  the  line  E,  or  from  C  to  F,  the  sizes  of  the 
wheels  are  determined.  These  lines,  E  F  and  D  F,  are  the  diam- 
eters for  the  pitch-lines  ;  from  them  the  form  of  the  tooth  is  de- 
scribed on  the  bevelled  face  of  the  wheel.  If  the  form  of  the  tooth 
is  described  on  the  largest  circle  of  the  wheel,  all  the  lines  from 
this  face  run  to  the  point  C,  so  that  when  the  wheel  revolves  around 
its  axis,  all  the  lines,  from  the  teeth  concentrate  in  the  point  C, 
and  form  a  perfect  cone.  Curvature,  thickness,  length,  and 
spaces  are  here  calculated  as  on  face  wheels;  the  thickness  is 
measured  in  the  middle  of  the  width  of  the  wheel. 


Worm-Screw. 

If  a  single  screw, 
A,  works  in  a  tooth- 
ed wheel,  each  rev- 
olution of  the  screw 
vill  turn  the  wheel 
one  cog;  if  the  screw 
is  formed  of  more 
than  one  thread,  a 
corresponding  num- 
ber of  teeth  will  be 
moved  by  each  rev- 
olution. With  the 
increase  of  the  num- 
ber of  threads,  the 
side  motion  of  the  wheel  and  screw  is  accelerated;  and  when  the 
threads  and  number  of  teeth  are  equal,  an  angle  of  45°  is  required 
for  teeth  and  thread,  provided  their  diameters  also  are  equal. 
This  motion  causes  a  great  deal  of  friction,  and  it  is  only  resorted 
to  where  no  other  means  can  be  employed  to  produce  the  re- 
quired motion.  In  small  machinery,  the  worm  is  frequently 
made  use  of  to  produce  a  uniform,  uninterrvipted  motion;  the 
screw  in  such  cases  is  made  of  hardened  steel,  and  the  teeth  of 
the  wheel  are  cut  by  the  screw  which  is  to  work  in  the  wheel. 
If  the  form  of  the  teeth  in  the  wheel  is  not  curved,  and  its  face 
is  concave  so  as  to  fit  the  thread  in  all  points,  the  screw  will 


156  WHEEL   GEARING. 

touch  the  teeth  but  in  one  point,  and  cause  them  to  he  liable  to 
breakage. 

Proportions  of  Teeth,  of  Wheels. 

Tooth.-  In  computing  the  diiiaensions  of  a  tooth,  it  is  to  be 
considered  as  a  beam  lixed  at  one  end.  the  weight  suspended 
from  the  othei",  or  face  of  the  beam  ;  and  it  is  essential  to  consid- 
er the  element  of  velocity,  as  its  stress  in  operation,  at  high  velo- 
city with  irregular  action,  is  increased  thereby. 

The  dimensions  of  a  tooth  shoiald  be  much  greater  than  is 
necessary  to  resist  the  direct  stress  upon  it,  as  but  one  tooth  is 
proportioned  to  bear  the  whole  stress  upon  the  wheel,  although 
two  or  more  are  actually  in  contact  at  all  times;  but  this  require- 
ment is  in  conse(^uence  of  the  great  wear  to  which  a  tooth  is  sub- 
jected, the  shocks  it  is  liable  to  from  lost  motion,  when  so  worn 
as  to  reduce  its  depth  and  uniformity  of  bearing,  and  the  risk  of 
the  breaking  of  a  tooth  from  a  defect. 

A  tooth  running  at  a  low  velocity  may  be  materially  reduced 
in  its  dimensions  compared  with  one  running  at  a  high  velocity 
and  witli  a  like  stress. 

The  result  of  operations  with  toothed  wheels,  for  a  long  period 
of  time,  has  determined  that  a  tooth  with  a  pitch  of  'S  inches 
and  a  breadth  7.5  inches  will  transmit,  at  a  velocity  of  G.OG 
feet  per  second,  the  power  of  5'J.  1 G  horses. 


To  compute  the  Depth  of  a  Cast  Iron  Tooth. 

1.  When  the  Stress  is  given. 

Rule. — Extract  the  square  root  of  the  stress,  and  multiply  it 
by  .02. 

Example. — The  stress  to  be  borne  b'y  a  tooth  is  4,886  lbs, ;  what 
should  be  its  depth  ? 

v/488GX.02  =  l.lins. 

2.  Whek  the  Hokse-Power  is  gi\'en. 

IlyTJ5. — Extract  the  square  root  of  tin;  quotient  of  the  horso*- 
power  dividi-d  by  the  velocity  in  feet  jier  second,  and  multiply 
it  by  .4(iG. 

Example. — The  horse-power  to  bo  transmitted  by  a  tooth  is 
no,  and  llie  velocity  of  it  at  its  pitch-line  is  ('>.(\t',  feet  i>er  second: 
what  sli(jidd  bo  the  depth  of  the  tooth  V 


\ 


/5?-.X.4GG:..  1.398  ins. 
/  G  111) 


To  compute  the  Horse-Power  of  a  Tooth. 
Rule.   -Multiply  tlie  pr.'ssure  at  the  jtitcli-line,  by  its  velocity 
in  feet  per  minute,  and  divide  tho  product  by  33,000. 


WHEEL   GEARING.  157 

CALCULATING  fsPEED. 
When  Time  is  not  taken  into  Account. 

Rule. — Divide  the  greater  diameter,  or  number  of  teeth,  by  the 
lesser  diameter  or  number  of  teeth,  and  the  quotient  is  the  num- 
ber of  revolutions  the  lesser  will  make,  for  one  of  the  greater. 

Example. — How  many  revolutions  will  a  pinion  of  20  teeth 
make,  for  1  of  a  wheel  with  125  ? 

125-^  20  =  6.25  or  6^  revolutions. 

To  find  the  Number  of  Revolutions  of  the  last,  to  one  of  the  first,  in  a 
Train  of  Wheels  and  Pinions. 

Rule. — Divide  the  product  of  all  the  teeth  in  the  driving  by 
the  product  of  all  the  teeth  in  the  driven;  and  the  quotient  equals 
the  ratio  of  velocity  required. 

Example  1. — Reqiiired  the  ratio  of  velocity  of  the  last,  to  1  of 
the  first,  in  the  following  train  of  wheels  and  pinions,  viz. :  pin- 
ions driving — the  first  of  which  contains  10  teeth,  the  second  15, 
and  third  18.  "Wheels  driven,  first,  15  teeth,  second,  25,  and 
third,  32. 

— — — —  =  .223  of  a  revolution  the  wheel  will  make  to  one  of 

15  X  25  X  32 

the  pinion. 

Example  2. — Awheel  of  42  teeth  giving  motion  to  one  of  12,  on 

which  shaft  is  a  pulley  of  21  inches  diameter  driving  one  of  6; 

required  the  number  of  revolutions  of  the  last  j)ulley  to  one  of 

the  first  wheel. 

42  X  "^1 

^  '    :=  12.25  or  12i-  revolutions. 
12  X  6  * 

Note. — "Where  increase  or  decrease  of  velocity  is  required  to  be 
commiinicated  by  wheel-work,  it  has  been  demonstrated  that  the 
number  of  teeth  on  each  pinion  should  not  be  less  than  1  to  6  of 
its  wheel,  unless  there  be  some  other  important  reason  for  a 
higher  ratio. 


When  Time  must  be  regarded. 

EuLE. — Multiply  the  diameter  or  number  of  teeth  in  the  driver, 
by  its  velocity  in  any  given  time,  and  divide  the  product  by  the 
required  velocity  of  the  driven;  the  quotient  equals  the  nuti;bor 
of  teeth  or  diameter  of  the  driven,  to  produce  the  velocity  re- 
quired. 

Example  1. — If  a  wheel  containing  84  teeth  makes  20  revolu- 
tions per  minute,  how  many  must  another  contain,  to  work  in 
contact,  and  make  60  revolutions  in  the  same  time? 

84X20  4- 60  =  28  teeth. 

Example  2.  —From  a  shaft  making  45  revolutions  per  minute, 
and  with  a  pinion  'J  inches  diameter  at  the  pitch  line,  I  wish  to 


15S  WHEEL   GEARING. 

transmit  motion  at  15  revolutions  per  minute;  wliat,  at  the  pitct/ 
line,  must  be  the  diameter  of  the  wheel  ? 

45  X  9  -T- 15  =  27  inches. 

Examples. — Required  the  diameter  of  a  pullej'  to  make  16 
revolutions  in  the  same  time  as  one  of  24  inches  making  36. 
24  X  36  -^  16  =  51  inches. 

The  Distance  heiween  Ike  Centres  ami  Vdociiies  of  Two  Wheels  being 
given,  to  find  their  Proper  Diameters. 

S-ULE. — Divide  the  greatest  velocity  by  the  least;  the  quotient 
is  the  ratio  of  diameter  the  wheels  must  bear  to  each  other. 

Hence,  divide  the  distance  between  the  centres  by  the  ratio  -j- 
1;  the  quotient  equals  the  radius  of  the  smaller  wheel;  and  suId- 
tract  the  radius  thus  obtained  from  the  distance  between  the 
centres;  the  remainder  equals  the  radius  of  the  other. 

Example. — The  distance  of  two  shafts  from  centre  to  centre  is 
50  inches,  and  the  velocity  of  the  one  25  revolutions  per  minute, 
the  other  is  to  make  80  in  the  same  time;  the  proper  diameters 
of  the  wheels  at  the  pitch  lines  are  required. 
80-^25  =  3.2,  ratio  of  velocity,  and  50-;- 3.2  +  1  =  11.9  the  radius 

oi"  the  smaller  wheel;  then  50  — 11.0  i=  38.1,  radius  of  larger; 

their  diameters  are  11.9  X  2  =  23.8  and  38.1  X  2  =  76.2  inches. 

To  obtain  or  diminish  an  accumulated  velocity  by  means  of 
wheels  and  pinions,  or  wheels,  pinions,  and  pulleys,  it  is  neces- 
sary that  a  proportional  ratio  of  velocity  should  exist,  and  which 
is  thus  attained;  multiply  the  given  and  reijuircd  velocities  to- 
gether; and  the  s<{uaro  root  of  the  product  is  the  mean  or  pro- 
portionate velocity. 

Example. — Let  the  given  velocity  of  a  wheel  containing  54 
teeth  equal  16  revolutions  per  minute,  and  the  given  diameter  of 
an  intermediate  piiUey  equal  25  inches,  to  obtain  a  velocity  of  81 
revolutions  in  a  machine;  required  the  number  of  teeth  in  the 
intermediate  wheel  and  diameter  of  the  last  pulley. 

v/81  X  16  =  36  mean  velocity; 
54  X  16-i-  36  =  24  teeth,  and 
25  X  36-1-81  =  11.1  inches,  diameter  of  pulley. 


Tablo  of  tho  Weight  of  a  Square  Foot  of  Sheet 
Iron  in  Pounds  Avoirdupois. 

No.  1  is  ,'',.,  of  an  inch;  No.  4,  {;  No.  11,  J,  Ac. 

No.  oil  win-gaugo,   1       2       3       4       5       6       7       8       9     10     11 
Pounds  avoir.,         12.5  12     11      10      9       8     7.5     7       6   5.68    5 

No.  on  wiro-gftugo,  12     13     It     IT)     16    17     18     19     20     21     22 
ToundH  avoir.,        4.62  4.31    1    3.',t5    3    2.5  2.18  1.93  1.62  1.5  1.3'? 


SCREW    CUTTING.  159 

SCREW  CUTTING-. 


In  a  lathe  iiroperly  adapted,  screws  to  any  degree  of  pitch,  or 
number  of  threads  in  a  given  length,  may  be  cut  by  means  of  a 
leading  screw  of  any  given  pitch,  accompanied  with  change  wheels 
and  pinions;  coarse  pitches  being  effected  generally  by  means  of 
one  wheel  and  one  jnnion  with  a  carrier,  or  intermediate  wheel, 
which  cause  no  variation  or  change  of  motion  to  take  place.  Hence 
the  following  ^^ 

KuiiE. — Divide  the  number  of  threads  in  a  given  length  of  the 
screw  which  is  to  be  cut,  by  the  number  of  threads  in  the  same 
length  of  the  leading  screw  attached  to  the  lathe;  and  the  quo- 
tient is  the  ratio  that  the  wheel  on  the  end  of  the  screw  must  bear 
to  that  on  the  end  of  the  lathe  spindle. 

Example. — Let  it  be  required  to  cut  a  screw  with  .5  threads  in 
an  inch,  the  leading  screw  being  of  X  inch  pitch,  or  containing  2 
threads  in  an  inch;  what  must  be  the  ratio  of  wheels  api^lied? 

5-^2  =  2.5,  the  ratio  they  must  bear  to  each  other. 

Then  suppose  a  pinion  of  40  teeth  be  fixed  upon  for  the  spindle: 

40  X  2.5  =  100  teeth  for  the  wheel  on  the  end  of  the  screw. 

But  screws  of  a  greater  degree  of  fineness  than  about  8  threads 
in  an  inch  are  more  conveniently  cut  by  an  additional  wheel  and 
pinion,  because  of  the  proper  degree  of  velocity  being  more  efi"ec- 
tively  attained;  and  these,  on  account  of  revolving  upon  a  stud, 
are  commonly  designated  the  stud-wheels,  or  stud-wheel  and  pin- 
ion; but  the  mode  of  calculation  and  ratio  of  screw  are  the  same 
as  in  the  preceding  rule.  Hence,  all  that  is  further  necessary  is 
to  fix  upon  any  3  wheels  at  pleasure,  as  those  for  the  spindle  and 
stud-wheels;  then  multiply  the  number  of  teeth  in  the  spindle- 
wheel  by  the  ratio  of  the  screw,  and  by  the  number  of  teeth  in 
that  wheel  or  pinion  which  is  in  contact  with  the  wheel  on  the 
end  of  the  screw;  divide  the  product  by  the  stud-wheel  in  con- 
tact with  the  spindle-wheel;  and  the  quotient  is  the  number  of 
teeth  required  in  the  wheel  on  the  end  of  the  leading  screw. 

ExAMPiiE. — Suppose  a  screw  is  required  to  be  cut  containing 
23  threads  in  an  inch,  and  the  leading  screw,  as  before,  havmg 
two  threads  in  an  inch,  and  that  a  wheel  of  60  teeth  is  fixed  upon 
for  the  end  of  the  spindle,  2  )  for  the  pinion  in  contact  with  the 
screw-wheel,  and  lUO  for  that  in  contact  with  the  wheel  on  the 
end  of  the  spindle;  required  the  number  of  teeth  in  the  wheel  for 
the  end  of  the  leading  screw. 

25  ^  2  =  12. 5,  and  ^^  ^  ^^^^  ^  ^^^  =  150  teeth. 

Or  suppose  the  sjiindle  and  screw-wheels  to  be  those  fixed 
upon,  also  any  one  of  the  stud-wheels,  to  find  the  niimber  of 
teeth  in  the  other. 

GO  X  12.5       „^^     .,         60X12.5X20       ,^^  ^    ^, 

150  X  100  ^  ^^  *'''^'  "' i50~~  =^  ''^  ''''^- 


160  WATER-WHEELS. 

WATER- WHEELS. 


The  properties  of  water,  as  a  motive  power,  are  gravity  and  im- 
pulsive force,  e.ach  being  renlereil  peculiarly  available  for  the 
production  of  uniform  circular  motion  through  the  medium  of 
the  water-wheel. 

Water-wheels  are  necessarily  and  designedly  of  various  modi- 
fications, so  as  to  obtain  the  greatest  amount  of  mechanical 
effect  from  a  known  quantity  of  water  llowing  at  a  certain 
A'clocity,  or  from  a  ^iven  height,  and  generallj'  ranked,  by 
estimation  of  effect,  into  first,  second,  and  third  class  wheels. 

1st  class  includes  overshot-wheels,  pitchback-wheels,  and  tur- 
bines. 

2d  class  consists  of  breast-wheels,  or  those  which  receive  the 
water  below  the  level  of  tlie  axis. 

And  3d  class  is  composed  of  undershot-wheels,  tub-wheels, 
and  llutter-wheels. 

The  most  modern  and  best-conducted  experiments  on  each 
description,  as  known  to  the  yjublic  at  i)resent,  are  those  by 
Poncelot  of  America,  and  of  Morin  in  Fnmce,  the  results  of 
which  are  as  follows: 

Ovcrsliot-wheels,  &c. ;  ratio  of  power  to  effect,  varies  from .  60  to  .80 
Lreast-wheels,  "  "  "  .45  to. 50 

Undershot-wheels,  etc.  "  "  "  .27 to. 30 

The  greatest  effect  is  obtained  by  an  overshot-M-hcel  when  the 
diameter  of  the  wheel  is  so  proportioned  to  the  height  of  the  fall, 
that  the  water  shall  flow  upon  the  wlieel  at  a  point  about  ^21 
degrees  distant  from  the  top  of  the  wheel. 

If  the  portion  of  the  total  descent  passed  through  by  the  water 
be  given,  then  the  velocity  of  the  circumference  should  bo  one- 
half  of  that,  due  to  this  height.  Therefore,  multiply  the  portion 
of  fall,  in  feet,  by  04.38,  and  the  S(jnare  root  of  the  pi'oduct  equals 
the  water's  vdocitj',  in  feet,  per  second.     Also, 

If  the  area  of  cross-section  of  tlie  overflow  be  multiplied  by  tho 
velocity  at  the  end  of  the  fall,  the  product  equals  the  quantity, 
in  cubic  feet,  per  second. 


Experiments  on  Overshot- Wheels. 

1.  Whi'ii  the  depth  of  water  in  the  reservoir  is  invariable,  the 
diameter  of  tlie  wheel  should  never  exceed  the  (entire  height  of 
the  fidl,  less  so  much  as  is  requisite  to  generate  a  i)roper  velocity 
on  eiiti'ring  the  bnclcets. 

2.  WIkto  the  deiith  of  water  in  the  reservoir  varies  consider- 
ably and  unavoidably,  an  advantage  may  be  obtained  by  ajiply- 
ing  a  larger  wheel,  dc^pendcnt  uj)on  tiie  extent  of  fluctuation, 
ainl  ratio  in  time,  that  tlie  water  is  at  its  highest  or  lowest  levels 
(biriii;,'  a  given  ]irolonged  ])eri.)<l.  If  t'lis  lie  a  ratio  of  equality, 
iu  lime  there  will  bo  no  advantage ;  and  hcnco,  in  practice,  tho  cases 


WATER-WHEELS.  161 

■w  ill  be  rare  wlien  any  advantage  will  be  obtained  by  the  use  of 
an  oversUot-wheel  greater  in  diameter  than  the  height  of  fall, 
minus  the  head  due  to  the  required  velocity  of  the  water  reach- 
ing the  wheel. 

3.  If  the  level  of  the  water  in  the  reservoir  never  falls  below  the 
mean  depth  of  the  reservoir,  when  at  the  highest  and  lowest,  and 
the  average  depth  bo  between  an  eighth  and  a  tenth  of  the  height 
of  the  fall,  then  the  avei'age  mechanical  force  of  the  large  wheel 
will  be  greater  than  that  of  the  small  one  ;  and  it  Mill  of  course 
retain  its  increased  advantage  at  periods  of  increased  depths  of 
the  reservoir. 

4.  That  a  positive  advantage  is  gained  by  a  wheel  revolving 
in  a  conduit,  varying  with  the  conditions  of  the  wheel  and  fall  of 
nearly  1 1  per  cent,  of  the  total  power. 


To  ascertain  the  Power  of  a  Water-Wheel. 

E,ULF. — Multiply  the  velocity  of  the  wheel,  in  feet,  per  minute, 
bj^  the  weight  of  the  water,  in  pounds,  expended  on  the  wheel 
in  the  same  time;  divide  the  product  by  the  co-efficient  of  i>ower 
to  eftect,  and  the  quotient  equals  the  mechanical  effect  of  the 
wheel,  expressed  in  horse-power. 

(  1st  class  wheels,     47,190 
Co-efficients  ^  2d  class        "  69,300 

( 3d  class  "  115,500 
Or  multiply  the  product  of  the  quantity  of  water  expended, 
in  cubic  feet,  per  minute,  and  the  velocity  of  the  wheel,  in  feet, 
in  the  same  time,  by  the  following  decimal  equivalents;  the  pro- 
duct will  be  the  number  of  horse-power  that  the  wheel  is  equal 
to  in  useful  effect. 

( l.st  class  wheels,  .00132"; 

Decimal  equivalents  }  2d  class        "        .000902 

( 3d  class        "        .000541 

Example. — Suppose  a  stream  of  water  flowing  on  an  overshot- 
wheel  at  the  rate  of  95  cubic  feet  per  minute,  and  the  velocity  of 
the  wheel's  periphery  etpials  6  feet  per  second,  or  360  feet  per 
minute;  required  the  efiect  of  the  wheel  in  horse-power. 
360  X  95X62.5 
iT\Q~) ^^  horse-power. 

Or,  360X95  X -001325  =  45.29       " 

Note. — When  the  fiiU  of  water  does  not  exceed  4  feet,  an  under- 
shot-wheel ought  to  bo  applied;  from  4  to  10  feet,  a  breast-wheel; 
and  from  10  feet  upward,  an  overshot  or  pitchback  wheel. 


To  ascertain  the  Power  of  a  Stream. 

KuLE. — Multiply  the  weight  of  the  water,  in  jiounds,  dis- 
charged in  one  minute  by  the  height  of  the  fall  in  feet ;  divide 
by  33,000,  and  the  quotient  is  the  answer. 

Example. — What  power  is  a  stream  of  water  equal  to  of  the 


152  WATER-WHEELSi 

following   dimensions,   viz.:    1  foot  deep  by  22  inches  broad, 
velocity  350  feet  per  minute,  and  fall  GO  feet;  and  v/hat  should  be 
the  size  of  the  wheel  applied  to  it  ? 
12  X  22  X  350  X  12^  1728  X  02^  X  60  feet  ^  33000  =  72.9.     Ans. 

Hei"ht  of  fall  GO  feet,  from  which  deduct,  for  admission  of 
water "^md  clearance  below,  15  inches,  which  gives  58.U  feet  for 
the  diameter  of  the  wheel. 

Clearance  above    3  )  ^5  j^^j^gg^ 
"         below  12  J 

The  power  of  a  stream,  applied  to  an  overshot-wheel,  produces 
effect  as  10  to  6.6. 

Then,  as  10  :  6.6  :  :  72.9  :  48  horse-power  equal  that  of  an  over- 
shot-wheel  of  GO  feet  applied  to  this  stream. 

When  the  fall  exceeds  10  feet  the  overshot-wheel  should  be  ap- 
plied. ,  T      1        1  i. 

The  higher  the  wheel  is  in  proportion  to  the  whole  descent, 
the  greater  will  bo  the  eifect. 

The  cfifect  is  as  the  quantity  of  water  and  its  perpendicular 
height  multiplied  together. 

The  weight  of  the  arch  of  loaded  buckets,  in  pounds,  is  found 
by  multipryiug  4-9  of  their  number,  X  the  number  of  cubic  feet 
in  each,  and  that  product  by  40. 


To  ascertain  the  Power  of  an  Undersliot-Wheel 
when  the  Stream  is  confined  to  the  Wheel. 

Rule. —Ascertain  the  weight  of  the  water  discharged  against 
the  floats  of  the  wheel  in  one  minute  by  the  ])receding  rules,  and 
divide  it  by  100,000;  th(!  quotient  is  the  number  of  horse-power. 

Note.— The  100,000  is  obtained  thus:  Tlie  power  of  a  stream, 
applied  to  an  undershot-wheel,  produces  effect  as  10  to  3.3;  then 
3.3  :  10  :  :  33,000  :  1(;0,000. 

When  tlie  opening  is  above  the  centre  of  the  floats,  multi])ly 
weight  of  the  water  by  tlie  height,  as  in  the  rule  for  an  overshot 
■wheel. 

Example. —What  is  the  power  of  an  undershot- wheel,  applied 
to  a  stream  2  by  80  inches,  from  a  head  of  25  feet  ? 

/25  X  6  5  X  60  —  19.')0  U-ct  velocity  of  water  ])er  minute,  and 
2  X  80  =  16')  inches  X  1950  X  12  X  1728  -^  21(i(;.(;  cubic  fec^t  X 
62.6  =  *135412  lbs.  of  water  discharged  in  one  minute;  then 
135412  -^  100000  —  1.35  horse-power. 


To  find  the  Power  of  a  Breast-Wheel. 

Role.— Find  thjMiffcctof  an  undershot-whed,  the  liead  of  water 
of  which  i8  the  diflferenco  of  level  between  the  surface  and  where  it 

•  Erinnl  160  X  12  -r- 1728  X  62.5  X  I'J^O  =  momentum  of  water 
I  nd  itH  velocity. 


WATER-WHEELS.  163 

strikes  the  wheel  (breast),  and  add  to  it  the  effect  of  that  of  an 
overshot-wheel,  the  height  of  the  head  of  which  is  equal  to  the 
difference  between  where  the  water  strikes  the  wheel,  and  the 
tail  water;  the  sum  is  the  effective  power. 

Example. — What  would  be  the  power  of  a  breast-wheel  applied 
to  a  stream  2  X  80  inches,  14  feet  from  the  surface,  the  rest  of 
the  fall  being  1 1  feet  ? 

,/  14  X  6.5  X  60  =r  1458.6  feet  velocity  of  water  per  minute. 

And  2X80X  1458X12 -f- 1728=:  1620  cubic  feet  X  62.5  = 
101250  lbs.  of  water  discharged  in  one  minute. 

Then  101250  -^  100000  =  1.012  horse-power  as  an  undershot. 

v/llX65X60  =  1290  feet  velocity  of  water  per  minute. 

And  2  X  80  X  1290  X  12  -I- 1728  =  1433  cubic  feet  X  62.5  = 
89562  lbs.  of  water  discharged  in  one  minute,  which 

X  1 1  height  of  fell  -i-  50000  =  19.703  horse-power,  which,  added 
to  the  above,  1=20.715.     Ans. 

Note.— When  the  fall  exceeds  10  feet,  it  may  be  divided  into 
two,  and  two  breast-wheels  applied  to  it. 

When  the  fall  is  between  4  and  10  feet,  a  breast-wheel  should 
be  applied. 

The  power  of  a  water-wheel  ought  to  be  taken  off"  opposite  to 
the  point  where  the  water  is  producing  its  greatest  action  upon 
the  wheel. 


Bemarks  on  Reaction  Water- Wlisels. 


Keaction  water-wheels  are  a  very  numerous  family,  of  which 
the  well-known  hydraulic  motor,  called  Barker's  mill,  is  the  pa- 
rent ;  those  used  in  various  parts  of  the  United  States  have  usually 
vertical  axes  of  rotation,  and  curved  buckets,  or  vanes,  against 
which  the  impulsive  force  of  the  water  (spouting  from  within  the 
wheel  by  adjutages,  of  which  the  curved  vanes  form  the  sides)  acts 
indirectly,  or  rather  reacts,  thus  producing  (in  reference  to  the 
affluent  water)  a  backward  rotary  motion,  similar,  in  character 
and  effect,  to  the  forward  rotary  motion  produced  by  direct  im- 
pulse in  the  case  of  undershot-wheels. 

In  the  American  Philosophical  Transactions  for  1793,  it  is 
stated  that  the  principles  of  reaction  wheels  had  been  fully  in- 
vestigated analytically  in  examining  the  merits  of  Rumsey's  im- 
provements on  Barker's  mill;  and  the  conclusion  come  to,  after  a 
train  of  reasoning  based  upon  scientific  principles, was,  that  "ac- 
tion and  reaction  are  equal;"  that  the  undershot-wheel  is  pro- 
pelled by  the  action;  and  Barker's  mill  by  the  reaction  of  the 
same  agent,  or  momentum;  therefore  their  mechanical  effects 
must  be  equal. 

This  conclusion  no  doubt  tended  to  retard  any  effort  at  im- 
provement of  wheels  on  that  principle  for  a  considerable  length 
of  time;  for  it  is  only,  comimratively  sjDeaking,  quite  recently 
that  reaction  water-wheels,  of  the  form  at  present  in  use,  have 
occupied  a  prominent  position  before  the  public. 


1G4  WATER-WHEELS. 

In  1830,  Calvin  Wing,  of  the  United  States,  took  otit  a  patent 
for  a  reaction  water-wheel  with  curved  vanes  or  buckets,  the 
vanes  of  which  lapped  over,  or  rather  on  to  each  other,  in  the 
ratio  of  li  inches  for  each  inch  of  the  width  of  the  adjutage,  or 
shortest  horizontal  distiuice  between  any  two  adjacent  vanes. 

In  this  wheel  the  water  has  free  entrance  to  a  circular  space 
within,  and,  sjiouting  out  by  the  oi>oniugs  between  the  curved 
vanes,  impels  the  wheel  around  in  a  backward  direction,  by  its 
reaction  against  the  vanes,  in  issuing  with  velocity  from  within 
the  wheel. 

But  this  species  of  wheel,  so  far,  seems  not  to  realize  the 
amount  of  effect  as  anticipated;  for,  according  to  rec(>nt  experi- 
ments, it  appe  rs  that,  with  788  cubic  feet  of  water,  at  the  rate  of 
one  foot  per  miniite,  ai>plied  on  an  overshot-wheel,  will  grind 
and  dress  one  bushel  of  wheat  per  hoiar;  where&s  to  do  the  same 
by  means  of  the  reaction  wheel  required  1,600. 

Some  of  later  date,  as  the  turbine  of  France,  by  M.  Fourney- 
ron,  and  the  recently  patented  water-mill,  by  Whitelaw  and  Stir- 
rat,  Scotland,  seem  much  improved  hydraulic  motors;  for,  ac- 
cording to  the  experiments  of  IVI.  Morin,  and  others  of  high  au- 
thority, they  rank,  in  effect  to  jjower,  equal  to  first-class  wheels. 

The  chief  objection  to  the  common  overshot-wheel,  is  its  great 
size  anl  formidable  cost,  to  whicli  might  be  added,  the  loss  of 
power  consequent  on  the  friction  of  the  gearing  requisite  for 
bringing  up  the  sjieed  of  the  prime  mover  to  the  velocity  indis- 
pensaljlc  to  most  ordinary  mechanical  operations.  These  objec- 
tions do  not  apply  to  this  species  of  water-power,  as  the  machine 
occupies  but  a  very  small  s]iace  in  comparison  witli  a  water-wheel 
of  the  same  power;  its  speed  is  high,  ixnd  tiie  expense  of  its  con- 
struction greatly  inferior  to  that  of  any  other  effectual  mechanism 
we  are  at  jjresent  acquainted  with  for  deriving  a  rotary  motion 
from  a  head  of  water. 

The  arms  of  the  machine  by  Whitelaw  and  Stirrat  are  bent  in 
the  form  of  ai  Archimedes  spiral,  so  as  to  obviate  tlie  communica- 
tion of  a  centrifugal  force  to  the  water,  which,  il*th(  arms  were 
straiglit,  it  would  necessarily  ac(iuire  to  the  diminution  of  tho 
useful  effect.  Any  number  of  arms  may  be  used,  but  two  is  the 
common  number.  The  machine  revolves  horizontally,  and  tlio 
afHucnci-  of  tho  water  at  tlio  orifices  of  tho  arms  is  regulated  by 
means  of  valves  of  a  p(!culiar  description,  governed  by  tho  cen- 
trifugal force  of  tho  machine,  or,  iu  other  words,  by  its  velocity. 


Turbines. 

In  liigh-prossuro  turbims  the  reservoir  (of  tho  wheel)  is  in- 
closed at  top,  and  the  water  is  a<lrriitt<!d  tlirougli  a  l)i})e  at  its 
side.  In  low-pressure,  tho  water  flows  into  the  reservoir,  which 
is  open. 

In  turbines  working  under  water,  the  height  is  measured  from 
tho  surface  (jf  the  wati-r  in  tlie  sui)ply  to  tlie  surface  of  the  dis- 
churged  water  or  ract; ;  and  when  they  work  in  air,  tlic  height  i« 


WATER-WHEELS.  165 

measured  from  the  surface  in  the  supply  to  the  centre  of  the 
wheel. 

In  order  to  obtain  the  maximum  effect  from  the  water,  the 
velocity  of  it,  when  leaving  a  turbine,  should  be  the  least 
l^racticable. 

The  efficiency  is  greater  when  the  sluice  or  supply  is  wide 
open,  and  it  is  less  affected  by  head  than  by  variations  in  the 
supply  of  water.  It  varies  but  little  with  the  velocity,  as  it  was 
ascertained  by  experiment  that  when  35  revolutions  gave  an 
effect  of  .6i,  55  gave  but  .G6. 

When  turbines  ojierate  under  water,  the  flow  is  always  full 
through  them;  hence  they  become  reaction- wheels,  Avhich  are  the 
most  efficient. 

The  experiments  of  Morin  gave  results  of  the  efficiency  of  tur- 
bines as  high  as  .75  of  the  power  exjjended. 

The  angle  of  the  plane  of  the  water  entering  a  turbine  with  the 
inner  periphery  of  it  should  be  greater  than  93°,  and  the  angle 
which  the  plane  of  the  water  leaving  the  i-eservoir  makes  with 
the  inner  circumference  of  the  turbine  should  be  less  than  90°. 

AVhen  turbines  are  constructed  without  a  guide  curve,*  the 
angle  of  plane  of  flowing  water  and  inner  circumference  of 
wheel  =  90=. 

Great  curvature  involves  greater  resistance  to  the  efflux  of  the 
water  ;  and  hence  it  is  advisable  to  make  the  angle  of  the  plane 
of  the  entering  water  rather  obtuse  than  acute,  say  100"  ;  the 
angle  of  the  plane  of  the  water  leaving,  then,  should  be  50°,  if 
the  internal  pressure  is  to  balance  the  external;  and  if  the  wheel 
operates  free  of  water,  it  may  be  reduced  to  25=  and  30°. 

The  angle  made  by  the  plane  of  the  discharged  water  with  the 
water  periphery  should  never  exceed  20°. 

Foiu'ueij roll's  wu-k  either  in  or  out  of  water,  are  applica- 
ble to  high  and  low  falls,  and  are  either  high  or  low  pressure 
turbines.  They  are  best  adapted  for  very  low  falls,  and  those  of 
moderate  height,  say  up  to  30  feet,  with  large  supplies  of  water. 
The  pressure  upon  their  step  is  confined  to  the  weight  of  the 
wh"el  alone. 

Fourneyron  makes  the  angle  of  the  plane  of  the  water  entering 
a  turbine  =  90°,  and  the  angle  of  the  jdane  of  the  water  leaving 
=  30°. 

Joiival's. — This  wheel  is  essentially  alike  in  its  principal 
proportions  to  Fontaine's,  and  in  the  principle  of  operation  it  is 
the  same.  The  water  in  the  race  must  be  at  a  certain  depth 
below  the  wheel. 

The  efficiency  of  this  wheel  decreases  as  the  volume  of  water  is 
diminished,  or  as  the  sluice  is  contracted. 

Fontaine 's. — In  the  operation  of  this  wheel  the  water  in  the 
race  is  in  immediate  contact  with  the  wheel,  and  its  efficiency  is 
greatest  when  the  sluice  is  fully  opened.     Its  efficiency,  also,  is 

♦Guide  curves  are  platos  upon  the  centre  body  of  a  turbinn.  which  give 
direction  to  the  flowing  water,  or  to  the  blades  of  the  wheel  which  surround 
them. 


1G6 


WATER. 


less  affected  by  variations  of  the  liead  of  the  flow  than  in  the 
volume  of  the  water  supplied  ;  hence  they  are  adajited  for  tide- 
mills. 

The  pressure  upon  the  step,  in  addition  to  the  weight  of  the 
•wheel,  includes  that  of  the  contained  water. 

Jflt  itrlaw's. —Ihia  wheel  is  best  adapted  for  high  falls  and 
small  volumes  of  water. 

Ponrclet's. — This  wheel  is  alike  to  one  of  his  undershot- 
wheels  set  horizontally,  and  it  is  the  most  simple  of  all  the 
horizontal  wheels. 

The  Katio  of  Effect  to  Powlr   of  the  sevekal  Toebines  is 

AS  follows  : 


Poncelet G5  to  .75  to  1 

Fourneyron 6    to  .75  to  1 

Whitelaw G    to  .75  to  1 


Jonval.  . . 
Fontaine 


.G  to 
.G  to 


7tol 
7tol 


A  Tremont  turbine,  as  observed  by  Mr.  Francis,  in  his  experi- 
ments at  Lowell,  ilass  ,  gave  a  ratio  of  effect  to  power  as  .79375 
to  1. 


WATER. 

To  FIND   TiiK   Quantity  of   Wateu  that  will  be   dischakgee 

THKOUGH    AN    OuiFICE    Oil   PiPE   IN     THE    SiDE    OE     BoTTOM    OF    A 

Vessel. 

Area  of  orifice,  sq.  in  X  \  No.  corresponding  to  height  of  sur-  ) 
^  j         lace  above  ontice,  as  j)er  table        ) 

=  cubic  feet  discharged  jJer  minute. 


Height 

Height 

HciRlit 

of  Surface 

Multiplier. 

of  Surface 

Multiplier. 

of  Surface 

Multiplier. 

above  Orifice 

above  Orifice 



above  Orifice 

Ft. 

Ft. 

Ft. 

1 

2.25 

18 

9.5 

40 

14.2 

2 

3.2 

20 

10. 

45 

15.1 

4 

4.5 

22 

10.5 

50 

IG. 

G 

.'■).14 

21 

11. 

GO 

17.4 

8 

G4 

2G 

11.5 

70 

18.8 

10 

7.1 

28 

12. 

80 

20  1 

12 

7.8 

'M 

12.3 

90 

21.3 

14 

H.l 

:V2 

12.7 

100 

22.5 

IG 

'J. 

35 

13.3 

WATER.  167 

to  find   the   size   of   hole  necessakt  to  discha.kge  a   given 
Quantity  of  Wateb  under  a  giten  Head. 

Cubic  ft.  water  discharged 

XT ^- ; — 1    ■  1  , r~cr  =  ^'^^a  of  onfice,  sq.  in. 

No.  corresponding  to  height,  as  per  table  '■ 

To  find  the  Height  necessary  to  dischakge  a  given  Quan- 
tity  THBOUGH  A   GIVEN    OeIFICE. 

Cubic  ft.  -water  discharged      ..^  ,    . 

Area  orifice,  sq.  inches    =^^^-  '°''^^'^-  *°  ^''-^^'  ^'  P^^  *^^^«- 

The  Velocity  of  Water  issuing  from  an  Obifice  in  the  Side 
OK  Bottom  of  a  Vessel,  being  ascertained  to  be  as  follows: 

v/ Height  ft.  surface  above  orifice  X  5.4=  -j  Velocity  of  water,  ft. 
°  j  per  second. 

v/ Height  ft.  X  area  orifice,  ft.  X  324=  [  ^^^^^^^  ^'^^^  discharged 
^         >=>  '  j  per  minute. 

s/  Height  ft.  X  area  orifice,  ins.  X  2.2  =         Do.  do. 

It  may  be  observed,  that  the  above  rules  rejjresent  the  actual 
quantities  that  will  be  delivered  through  a  hole  cut  in  the  plate; 
if  a  short  pipe  be  attached,  the  quantity  will  be  increased,  the 
greatest  delivery  with  a  straight  pij^e  being  attained  with  a  length 
equal  to  4  diameters,  and  being  1-^  more  than  the  delivery 
through  the  plain  hole;  the  quantity  gradually  decreasing  as  the 
length  of  pipe  is  increased,  till,  with  a  length  equal  to  GU  diam- 
eters, the  discharge  again  equals  the  discharge  through  the  plain 
orifice.  If  a  taper  jiipe  be  attached,  the  delivery  will  *be  still 
greater,  being  U  times  the  delivery  through  'the  plain  orifice; 
and  it  is  probable,  that  if  a  pipe  with  curved  decreasing  taper 
were  to  be  tried,  the  delivery  through  it  would  be  equal  to  the 
theoretical  discharge,  which  is  about  1.65  the  actual  discharge 
through  a  plain  hole. 

To  FIND  the  Quantity  of  Water  that  will  run  through  any 
Orifice,  the  Top  of  which  is  level  -with  the  SSurkace  of 
Water,  as  over  a  Sluice  or  Dam 

/Height  ft.  from  water-surface  to  bot-  |  Area  of  water-  l^n-in 
V  torn  of  orifice  or  top  of  dam  \  ^  jiassage,  sq.ft.  j"  ^  -iio 

=  cubic  ft.  discharged  per  minute. 

Two-thirds  area  of  water-passage,   sq.  ins.  X  No.   corresponding 
to  height,  as  per  table  =  cubic  feet  discharged  per  minute. 

To   FIND    the    time    IN    WHICH    A   VeSSEL   WILL   EMPTY   ITSELF 
through    a    given    ORIFICE. 

y/  Height  ft.  surface  above  orifice  X  area  water-surface,  sq  ins. 

Area  orifice,  sq.  in.  X  3.7  ~" 

=  Time  required,  seconds. 

The  above  rules  are  founded  on  Bank's  experiments. 


16.S 


SPECIFIC   GRAVITIES. 


TABLE   OP   SPECIFIC   GRAVITIES. 


Liquids. 

Di'vide  the  Specific  Gravity 
by  16,  and  the  quotieut  is 
the  weight  oi  a  cubic  foot      Specific 
in  lbs.  Gravity. 

Acid,  acetic 1.0(32 

"     nitric 1.217 

"     sulphuric 1.841 

"     muriatic 1.200 

Alcohol,  pure 7i)2 

"         of  commerce 835 

Oil,  essential,  turpentine.   .870 

"     olive 915 

"     whale 925 

"     linseed 9;J2 

Proof  spirit 925 

Vinegar   1.080 

Water,  distilled    1.000 

Ether,  sulphuric 715 

Honey 1.450 

Human  blood 1.054 

Milk 1.032 

W  ater,  sea 1. 020 

Dead  Sea 1.240 

Wine 992 

"     port 997 

"    champagne 997 


Elastic  Fluids. 

Divide  the  Sppcific  Gravity 
by  16,  and  the  quoticut  is 
the  weight  of  a  cubic  foot      Specific 
in  lbs.  Gravity 

1  cuV)ic  ft.  of  atmospheric 
air   weighs   527.04  troy 
grains. 
Its  assumed  gravity  of  1  is 
the  unit  of  elastic  fluids  .1.000 

Ammoniacal  gas 597 

Azote   97() 

Carbonic  acid 1.524 

Carbureted  hydrogen 555 

Chlorine 2.470 

Chloro-carbonic 3.389 

Hydrogen 070 

Oxygen 1.1('4 

Sulphureted  hydrogen. . .  .1.777 

Steam,  212° 490 

Nitrogen 972 

Vapor  of  alcohol 1.613 

"       turpentine  spts  .5.013 

water    023 

Sinoke  of  bituminous  coal.  .102 
"      wood 900 


Metals. 


Divide  tlie  Rpociflc  Gravity 
by  16,  and  tlie  quotient  JH 
the  weight  ol  a  cubic  foot      Rpedflc 
lu  IbH.  Gravity. 

Antimony 0.712 

Arsenic 5. 703 

histuuth 9.823 

IJrass,  common     7.820 

Brf>nze,  gun-metal H.V'iO 

Copper,  ca.st 8.788 

"         wire  drawn.    .  .     8.878 

Gold,  pure,  cast 19.258 

"      hammend   19.301 

••      'n  carats  finf* 17.4S0 

"      20  carats  line    15.7ii9 

Iron,  coHt 7.207 


Divide  the  Specific  Gravity 
by  16.  and  th(!  (piotieDt  is 
tlie  weight  of  a  cubic  foot      Specific 
lu  lbs.  Gravity. 

Iron  bars   7.788 

L.'ad,  east   11.352 

Mercury,  32^ 13.598 

00'' 13,580 

riatinum,  rolled   '22.009 

haiiimored 20.337 

Silver,  i>nre.  cast   10.474 

"      iiamuiered    1((.511 

Steel,  soft  7.833 

"     teinp'd  and  hard'd    7.818 

Tin,  Cornish 7.291 

Zinc,  cast   (!.801 


HYDRAULICS.  160 

HYDRAULICS. 


The  science  of  hydrodynamics  embraces  hydrostatics  and  hy- 
draulics, the  former  of  which  treats  of  the  properties  and  equi- 
librium of  liquids  in  a  state  of  rest,  and  the  latter  of  liquids  in 
motion,  as  conducting  water  in  pipes,  raising  liquids  by  pumps, 
&c. 

1.  The  peculiar  distinguishing  properties  of  liquids  or  fliiids 
in  general  are,  capability  of  flowing,  and  constant  tendency  to 
press  outward  in  every  direction. 

2.  Fluids  are  of  two  kinds,  aeriform  and  liquid,  or  elastic  and 
non-elastic;  that  is,  bodies  of  which  are  easily  compressed  into  a 
smaller  bulk,  and  bodies  which  are  scarcely  susceptible  of  com- 
pression. Atmospheric  air,  steam,  or  vapor  of  water,  and  all 
other  gaseous  bodies,  are  of  the  first  kind;  and  water,  alcohol, 
mercury,  &c.,  are  of  the  second. 


Compression  of  Liquids,  in  Millionth  Parts  per 
Atmosphere. 

Mercury,  2.65] 

Alcohol,  21.60       /..i    •        •   •     1  -u   n 

Water,  46. 63     °^  *^^^^  ^^^g^^'^^  ^"^^• 

Ether,  61.58  J 

3.  The  weight  of  water  or  other  fluid  is  as  the  quantity,  but 
the  pressure  exerted  is  as  the  vertical  height. 

4  Fluids  press  equally  in  all  directions;  hence,  any  vessel 
containing  a  fluid  sustains  a  pressure  equal  to  as  many  times  the 
weight  of  the  column  of  greatest  height  of  that  fluid,  as  the  area 
of  the  vessel  is  to  the  sectional  ai-ea  of  the  column. 

5.  The  hydraulic  press  is  of  this  principle.  A  jet  of  water  is 
thrown  into  a  cavity  by  means  of  a  force  pump;  the  action  and 
non-compressible  property  of  the  liqi;id  repels  a  jiiston  or  ram, 
the  force  of  which  equals  the  product  of  the  effective  power  or 
pressure  exerted  on  the  fluid  in  the  pump,  multiplied  by  the 
number  of  times  the  area  of  the  base  of  the  ram  exceeds  the  sec- 
tional area  of  the  pump. 

ExAMPLK. — Reqiaired  therei^ulsive  force  of  a  six-inch  ram,  when 
a  power  of  50  lbs.  is  ai^plied  to  the  end  of  the  lever,  which  is  as  12 
to  1,  and  the  diameter  of  the  pump  or  plunger  7-8  of  an  inch. 

Area  of  ram     =  28. 2744       , ^ 

• •  —  47  ' 

Area  of  pump  =    .6013  ' 

and  50  X  12  X  47  =  28,230  lbs.,  or  12  tons,  nearly. 

6.  The  lateral  pressure  of  a  fluid  on  the  sides  of  any  vessel  in 
which  it  is  contained  is  equal  to  the  product  of  the  length  multi- 
plied by  half  the  stpiare  of  the  depth,  and  by  the  weight  of  the 
fluid  in  cubic  unity  of  dimensions. 

8 


170  HYDRAULICS. 

Example. — A  cistern   12  feet  square  find  8  feet  deep  is  filled 
with  water;  required  the  whole  amoiint  of  lateral  pressure. 
(Weight  of  a  cubic  foot  of  water,  62.5  lbs. ) 

12  X  4  =  48  feat,  the  whole  length  of  sides, 

,8^      -„      ,,       48X32X62.5       ... 

and  _-  =  32 ;    then — — =  48  tons  net. 

2  2uOj 

7  Fluids  alwaj's  tend  to  a  natural  level,  or  curve  similar  to  the 
earth's  convexity,  every  point  of  which  is  equally  distant  from 
the  centre  of  the  earth,  the  apparent  level,  or  level  taken  bj'  any 
instrument  for  that  purpose,  being  only  a  tangent  to  the  earth's 
circumference;  hence,  in  levelling  for  canals,  Ac,  the  difference 
causi'd  by  the  earth's  curvature  must  be  deducted  from  apparent 
level  to  obtain  the  true  level. 


When    the 
distance   is ' 


Feet, 

Yards, 

Chains 


To  find  the  Difiference  between  True  and  Apparent 

Level. 

r.f 00000287 ]     equal  the 
the  square      |  j  difference  in 

of    that        I    nnnnn^r^sT  I  inches  when 
distance       ]  -OOOOOioSJ  |-  refraction  is 

multiplied  by  |  |     not  taken 

[.00125         J  into  account. 

If  the  distance  is  considerable,  and  refraction  must  be  attended 
to,  diminish  the  distance  in  respect  to  calculation  by  1-12. 

Ex^vMPLE.  What  is  the  difference  between  true  and  apparent 
level  at  a  distance  of  18  chains,  when  refraction  is  taken  into 
account  ? 

18 

-5^1.5,  and  18  — 1.5  =  16.5"  X. 00125  =  .3133  inch. 

1a 

8.  When  a  body  is  partly  or  wholly  immersed  in  a  fluid,  the 
vertical  pressur('  of  the  fluid  lends  to  raise  the  body  with  a  force 
equal  to  the  W(Mght  of  tlic  fluid  displaccil;  hence,  the  weight  of 
any  displaccul  (juaiitity  of  a  fluid  by  a  buoyant  body  equals  the 
wtaght  of  that  body. 

9.  The  centre  of  i)rcssure,  and  also  the  centre  of  percussion  in 
a  fluid,  is  two-thirds  tlie  dei)th  from  the  surface. 

10.  Th(!  r<'sistanc(!  by  whi(!h  a  moving  body  is  oj)posed  in  jiass- 
ing  through  a  liquid  is  as  the  K(|uare  of  its  velocity:  hence,  if  a 
body  be  projiclhtd  at  a  certain  vcdocity  by  a  known  i>ow('r,  to 
doubli'  that  velocity  will  reciuire  four  times  the  power;  to  triple 
it,  nine  times  the  power,  &c. 


Of  Liquids  in  Motion. 

Tlie  flowing  of  water  through  pipes,  or  in  natural  channels,  is 
lialili;  to  b(!  materially  attcctc'd  by  friction.  Water  flows  smoothly 
and  with  least  retardation  wlieii  the  course  is  i)erfectly  smooth 
and  straight.  ICvery  little  inr-quality  which  is  present(^d  to  the 
liquid  tends  to  retard  its  motion,  and  so  likewise  docs  every 
bend  or  angle  in  its  path. 


HYDRAULICS. 


171 


1.  When  water  issues  out  of  a  circular  aperture  in  a  thin  plate 
on  the  bottom  or  side  of  a  reservoir,  the  issuing  stream  tends  to 
converge  to  a  point  at  the  distance  of  about  half  its  diameter  out- 
side the  orifice,  and  this  contraction  of  the  stream  reduces  the 
area  of  its  section  from  1  to  .66G,  according  to  Bossut  ;  to  .631, 
according  to  Venturi ;  and  to  .64,  according  to  Eytelwein.  But, 
from  more  accurate  experiments,  it  is  found  that  the  quantity 
discharged  is  not  sufficient  to  fill  this  section  with  the  velocity 
due  or  corresponding  to  the  height,  and  that  the  orifice  must  be 
diminished  to  .619,  or  nearly  f. 

1.  When  water  issues  through  a  short  tube,  the  vein  of  the 
stream  is  less  contracted  than  in  the  former  case,  in  the  propor- 
tion of  16  to  13  ;  and  if  it  issues  through  an  aperture  which  is 
the  frustum  of  a  cone,  whose  greater  base  is  the  aperture,  the 
height  of  the  frustum,  half  the  diameter  of  the  aperture,  and  the 
area  of  the  small  end  to  the  area  of  the  large  end  as  10  to  16, 
there  will  be  no  contraction  of  the  vein.  Henc«,  when  the 
greatest  possible  supply  of  water  is  required,  this  form  of  orifice 
ought  to  be  employed. 


Table, 

Showing  the  Quantity  of  Wateb  dischaeged  per  Minute  bt  Ex- 

PEEIMENTS  WITH  OeITICES  DIFFERING  IN  FoRM  AND  POSITION. 


Constant  Weight 

Number  of 

of  the  fluid  above 

Form. 

Position. 

Diameter  of 
the  Orifice. 

Cubic  Inches 

the  centre  of  the 

discharged 

Orifice. 

per  minute. 

FT.    IN.    LINES. 

11     8      10 

Circular. 

Horizontal. 

6  lines. 

2.311 

(( 

n 

12     " 

9.281 

(( 

ft 

24     " 

37.203 

Rectangular. 

li 

12  by  3. 

2.933 

Square. 

It 

12  side. 

11.817 

(( 

it 

21     " 

47.361 

9    0        0 

Circular. 

Vertical. 

6  lines. 

2.018 

(( 

(( 

12     " 

8.135 

4    0         0 

n 

a 

6     " 

1.353 

(< 

a 

12     " 

5.436 

5     0         7 

(C 

a 

12     " 

.628 

Deductions  from  the  Preceding  Experiments. 

1.  That  the  quantities  of  water  discharged  in  equal  times  by 
the  same  orifice,  from  the  same  head  of  water,  are  nearly  as  the 
areas  of  the  orifices. 

2.  That  the  quantities  of  water  discharged  in  equal  times  by 
the  same  orifices,  under  different  heads,  are  nearly  as  the  square 
roots  of  the  corresponding  heights  of  the  water  in  the  reservoir, 
above  the  surface  of  the  orifices. 


1Y2  HYDRAULICS. 

3.  That  the  quantities  of  water  discharged  during  the  same 
time  by  difierent  apertures,  under  different  heights  of  water  in 
the  reservoir,  are  to  one  another  in  the  compound  ratio  of  the 
areas  of  the  aportiires,  and  of  the  square  roots  of  the  heights  in 
the  reservoir. 

4.  That,  on  account  of  the  friction,  small  orifices  discharge 
proportionally  less  lluid  than  those  which  are  larger  and  of  simi- 
lar figure,  under  the  same  altitude  of  fluid  m  the  reservoir. 

5.  That,  in  consequence  of  a  slight  augmentation  which  the 
contraction  of  the  fluid  vein  undergoes,  in  jjroportion  as  the 
height  of  the  fluid  in  the  reservoir  increases,  the  expenditure 
ought  to  be  a  little  diminished. 

6.  That  circular  apertures  are  most  advantageous,  as  they  have 
less  rubbing  surface  under  the  same  area. 

7.  That  the  discharge  of  a  fluid  through  a  cylindrical  horizon- 
tal tube,  the  diameier  and  length  of  which  are  equal  to  one 
another,  is  the  same  as  through  a  simple  orifice. 

8.  That  if  the  cylindrical  horizontal  tube  be  of  greater  length 
than  the  extent  of  the  diameter,  the  discharge  of  water  is  much 
increased,  and  may  be  increased  with  advantage  to  four  times 
the  diameter  of  the  orifice. 


Weight  of  Water  at  its  Common  Temperature. 

1         cubic  inch  =      .03(J17  lbs. 

12  "     inches  =     .434        " 

1  "     foot  =G2.5  " 

1  "        "  =   7.81  gallons. 

1.6         "     feet  =    1  lb. 

32  <<       '«  =1  ton. 

1  cylindrical  inch  =      .02^42  lbs. 

12  "  inches  =     .341        " 

1  "         foot  =49.1  «' 

1  "  "  =   6.130  gallona 

2.036  "  feet  =    1  cwt. 

40.73  "  "  =1  ton. 

12.5  gallons  ^^   1  cwt. 

250  "  =1  ton. 


On  the  Discharge  of  Water  by  Horizontal  Conduit, 
or  Conducting  Pipes. 

1.  The  less  the  diameter  of  the  pipe,  the  less,  proportionally, 
is  the  discliarge  of  fluid. 

2.  The  greater  the  hmgth  of  conduit  pipe,  the  greater  tha 
diminution  of  discharge. 

3.  Tlie  dischargrs  made  in  etjual  times,  by  horizontal  pipes  of 
diflfenint  b'ngtlis,  but  of  the  samc!  diameter,  and  undi-r  tlio  same 
altitude  of  wat<r,  are  to  one  anotht^r  in  the  inverse  ratio  of  tha 
square  roots  of  the  lengths. 

i.  That  in  order  to  have  a  perceptible  ami  continuous  disi 


HYDRAULICS.  173 

charge  of  fluid,  the  altitude  of  the  water  in  the  reservoir,  above 
the  axis  of  the  conduit  pipe,  must  not  be  less  than  148  inches 
for  every  180  feet  of  the  length  of  the  pipe. 

5.  That  in  the  construction  of  hydraulic  machines,  it  is  not 
enough  that  elbows  and  contractions  be  avoided,  but  also  any 
intermediate  enlargements,  the  bad  effects  of  which  are  propor- 
tionate, as  in  the  following: 

Head  of  Water,  in  Cubic     Number  ol  Enlarged     Seconds  in  which  4  Cubic 
Inches.  Parts.  Feet  were  discharged. 


32,5  0  109 

32.5  1  147 

32.5  3  192 

32.5  5 240 

Practical  Rules  and  Examples  for  ascertaining  the 
Diameters  of  Pipes,  and.  Quantity  of  Water  dia- 
charged  in  any  given  time. 

Rule. — Multiply  2,500  times  the  diameter  of  the  pipe,  in  feet, 
by  the  height  in  feet,  and  divide  the  product  by  the  length  in 
feet,  added  to  50  times  the  diameter,  and  the  square  root  of  the 
quotient  will  be  the  velocity  of  discharge  in  feet  per  second. 

Example. — Suppose  the  diameter  of  a  pipe  to  be  .375  foot ;  the 
height  of  the  water  in  the  reservoir,  above  the  point  of  discharge, 
51.5  feet,  and  the  length  of  pipe  14,637  feet.  Required  the  velo- 
city of  the  water,  and  the  quantity  discharged  in  cubic  feet  per 
second  ? 

2500  X.  375X51. 5      48281.25  .„.      ,_..„    ,  , 

-.„„„  V — — — ;r,^^  =  ^,^.r  n-  =  v/  3. 3  =  1. 816  fcct  per  second, 
14637  + (50  X- 375)      146o5.7o       ^  '■  ' 

velocity ; 

And  .375-2  X  •7854x1-816  =  .20057  cubic  foot  per  second. 

Or,  multiply  1,542,  133  times  the  fifth  power  of  the  diameter  of 
the  pipe  in  feet,  by  the  height  in  feet,  and  divide  the  product 
by  the  length  in  feet,  added  to  50  times  the  diameter  in  feet, 
and  the  square  root  of  the  quotient  equals  the  discharge  in 
cubic  feet  per  second. 

These  rules  apply  only  to  the  case  where  the  pipe  is  straight. 
If  there  be  bends  in  it,  the  velocity  (found  by  the  rule  as  above) 
must  be  diminished,  by  taking  the  product  of  its  square,  multi- 
plied by  the  sum  of  the  sines  of  the  several  angles  of  inflection, 
and  by  .0038,  which  will  give  the  degree  of  pressure  required  to 
overcome  the  resistance  occasioned  by  the  bends,  and  deducting 
this  height  from  the  height  corresponding  to  the  velocity,  the 
corrected  velocity  is  obtained. 

If  power  is  to  be  obtaioed  by  the  issuing  stream  of  water 
through  a  pipe,  the  whole  of  the  power  due  to  the  height  which 
is  necessary  to  send  the  water  through  the  pipe,  at  the  required 
velocity,  is  not  lost,  for  the  power  due  to  this  velocity  is  still  in 
the  water.     Thus,  suppose  five-tenths  or  half  a  foot  of  head  of 


174 


HYDRAULICS. 


water  be  given  to  maintain  a  required  velocity  of  water  througli 
a  pipe,  and  this  velocity  be  found,  as  per  rule,  to  be  2.988  feet 

per  second:  then  T^^^^^  V-  =  .1395    or  the  height    that  would 

give  that  water  a  velocity  of  2.988  per  second.  Hence,  .5  — 
.1395  =  .3605  of  a  foot,  the  positive  height  lost  by  the  resistance 
in  passing  through  the  pipe. 

A  pressure  of  .  75  of  a  foot  in  height,  will  give  a  velocity  of  dis- 
charge equal  to  3.5355  feet  per  second,  at  the  lower  end  of  a 
straight  pipe  of  2  feet  diameter  and  2UU  feet  in  length  ;  but  if 
there  be  a  bend,  or  number  of  bends,  in  the  pipe,  the  velocity  of 
the  water  will  not  be  so  great.  Say  that  there  are  three  bends, 
one  of  90',  and  the  other  two  of  150°  each,  the  sura  of  the  sines 
of  those  angles  equal  2.  Hence,  3.5355-  X  2  X  .(038 r=. 095,  and 
.  75  — .  095  ;=  .  655,  that  must  be  used  or  taken  instead  of .  75  in  the 
rule  for  obtaining  the  velocity  of  discharge  at  the  lower  end  of 
the  pipe. 

As  an  apiiroximate  rule  for  determining  the  diameters  of  pipes 
capable  of  conducting  any  required  quantity  of  water  in  cubic 
feet  per  minute  : 

Multiply  the  sqiiare  of  the  quantity  in  cubic  feet  per  minute 
by  .96,  and  the  jjroduct  equals  the  diameter  of  the  pipe  in 
inches. 

Ex.^MPLE.— Required  the  diameter  of  a  pipe  large  enough  to 
conduct  625  cubic  feet  of  water  i)er  minute. 

y/  625  =  25,  and  25  X  .96  =  24  inches  diameter. 


Diameter  of  Pipes  sufficient  in  size  to  discharge  a 
required  Quantity  of  Water  per  Minute. 


Cub.  ft 

Diam.  in  inches. 

Cub.  ft. 
18 

Diam.  in  inches 

Cub.  ft. 

Diam. in  iDches. 

1 

.96 

4.07 

130 

10.94 

2 

1.36 

20 

4.29 

140 

11.35 

3 

1.66 

25 

4.80 

150 

11.75 

4 

1.92 

30 

5.25 

1(50 

12.14 

5 

2.15 

35 

5.67 

170 

12.51 

6 

2.35 

40 

6.07 

180 

12.67 

7 

2.60 

45 

(i.53 

190 

13.23 

8 

2.72 

50 

6.80 

200 

13.57 

9 

2. 88 

55 

7.12 

225 

14.40 

10 

3.04 

(JO 

7.43 

250 

15.1 

11 

3.18 

70 

8.03 

275 

15.91 

12 

3.33 

<() 

8  60 

3;)0 

16.62 

13 

.3.46 

90 

9.10 

350 

17.95 

14 

3.60 

100 

9.60 

400 

19.20 

15 

3.72 

110 

10.06 

500 

20.46 

16 

3.84 

120 

1 

10.51 

600 

23.51 

HYDRAULICS.  175 

Of  the  Discharge  of  Wate.-  by  Kectangular  Orifices 
in  the  Side  of  a  beservoir  extending  to  the  Sur- 
face. 

The  velocity  of  the  water  varies  nearly  as  the  square  root  of  the 
height,  and  the  quantity  discharged  per  second  two-thirds  of  the 
velocity  due  to  the  mean  height,  allowing  for  the  contraction  of 
the  fluid,  according  to  the  form  of  the  opening,  which  renders 
the  co-efficient  in  this  case  equal  to  5. 1.     Hence, 

Suppose,  in  the  side  of  a  lake  or  in  the  side  of  a  reservoir,  a 
rectangular  opening  is  made,  without  any  oblique  lateral  walls, 
3  feet  wide,  and  extending  2  feet  below  the  surface  of  the  water. 
Kequired  the  quantity  that  will  be  discharged  in  cubic  feet  per 
second. 

The  area  of  the  opening  =  3  X  2  =  6  ft. ;  and  §  of  y  2  X  o.  1  X  6 
=  28.85  cubic  feet. 

The  same  co-efficient  is  applicable  to  the  finding  of  the  dimen-s 
sions  of  a  weir  in  the  side  of  a  lake  or  in  the  side  of  a  still  river. 

For  example : 

In  the  side  of  a  lake  is  a  weir  of  3  feet  in  breadth,  and  the  sur- 
face of  the  water  stands  5  feet  above  it.  How  much  must  the 
weir  be  widened,  in  order  that  the  water  may  be  a  foot  lower,  and 
an  equal  quantity  discharged  ? 

Here,  the  velocity  is  §  the  y  5  X  5.1,  and  the  quantity  of  water 

fv/ 5X5.1X3X5; 

but  the  velocity  must  be  reduced  to  §  of  y/ 4  X  5.1, 

,^      ^,  ,.  .„,     §v/ 5X5.1X3X5        v/5x3x5      __ 

then  the  section  will  be     -   „     .  .  ^-   _  , = y-. =  7.5; 

fv/*Xo.l  ^/  \. 

7  5 
and  -^  X  v/  5  =  4. 19  feet  in  breadth. 


Of  the  Motion  of  Water  in  Rivers. 

The  velocity  of  the  water  in  a  river  decreases  from  or  near  the 
surface  downward;  so  that  the  mean  velocity  under  any  point  of 
the  surface  will,  on  this  account,  be  less  than  that  obtained  by  a 
float  or  light  body  swimming  on  the  surface  of  the  fluid.  But 
after  having,  by  means  of  a  float,  determined  the  velocity  at  the 
surface,  at  any  particular  point  of  the  width  of  the  stream,  the 
mean  velocitv  of  the  water,  iiassing  under  that  point,  and  also 
the  velocity  at  the  bottom,  will  be  obtained  by  the  following 
rules  : 

1.  Take  1.03  from  the  square  root  of  the  velocity  at  the  sur- 
face, and  the  square  of  the  remainder  will  be  the  velocity  at  the 
bottom. 

2.  Add  the  surface  and  bottom  velocities  together,  and  half  the 
sum  is  the  mean  velocity. 


176 


HYDllAULICS. 


Table, 

Containing  the  Quantities  of  Watek,  in  Cubic  Feet,  that  will 

BE  discharged  OVEK  A  WeIK  PER  MiNUTE,  FOR  EVERY  InCH  IN  ITS 

Breadth,  when  the  Depth  of  the  Water  from  the  Surface  to 
THE  Top  Edge  of  the  Wasteboard  does  not  exceed  18  inches. 


Depth  of  the 

Cubic  Feet 
per    Minute. 

Ciil  ic  Feet 
per    Mloiitc, 

Depth  of  the 

CuMo  Feet 
per   Minute, 

Cubic  Feet 
per  Mlnuie, 
according  to 

Water,  in 
InchcB. 

according  to 
Du  Buafs 
Formula. 

Experiinenta 
nm'le    In 
Scotland. 

Water  In 
Indies. 

a<*rorttli»k'  to 
Du  Hnat'a 
Formula. 

Kxpmrinienta 
made  in 
Scotland, 

1 

0.403 

0.428 

10 

12.748 

13.535 

2 

1.110 

1.211 

11 

14.707 

15.632  • 

3 

2.095 

2.226 

12 

16.758 

17.805 

4 

3.225 

3.427 

13 

18.895 

20.076 

5 

4.507 

4.789 

14 

21.117 

22.437 

6 

5.925 

6.295 

15 

2^419 

24.883 

7 

7.466 

7.933 

16 

25.800 

27.413 

8 

9.122 

9  692 

17 

28.258 

30.024 

9 

10.884 

11.. 564 

]8 

30.786 

33  710 

To  find  the  Velocity  of  "Water  issuing  through  a  Cir- 
cular OrifiLce  at  any  given  Depth  from  the  Surface. 

Rule.  — ^Iiiltii)ly  tht;  stjuarc  root  of  tho.  lioi<^'ht  or  depth  to  the 
centre  of  the  orilice  by  8.1,  and  the  in-oduct  is  the  velocity  of  the 
issuing  fluid  in  feet  per  second. 

Example. --Required  the  velocity  of  water  issuing  through  an 
orifice  under  a  head  of  11  feet  from  the  surface. 

s/n  =  3.3166  X  8.1  =  26.864  feet  velocity  per  second. 

In  the  discharge  of  water  by  a  rectangular  aperture  in  the  side 
of  a  reservoir,  and  extending  to  the  surface,  the  velocity  varies 
nearly  as  the  square  root  of  the  height,  and  the  quantity  dis- 
chargf^d  per  second  ecjual  2-3  of  the  velocity  due  to  the  mean 
height,  allowing  for  the  contraction  of  the  fluid  according  to  the 
form  of  the  oi)ening,  wliidi  n-ndors  the  co-efhcient  in  this  case 
equal  to  5.1;  whence  the  following  gi^^-ncral  rules  : 

1.  When  the  Aperture  exlcmh  to  the  Surface  of  the  Fluid.  —Multiply 
the  are^v  of  the  opening  in  feet  by  the  square  root  of  its  depth 
also  in  feet,  and  that  product  by  5.1;  tlum  2-3  of  the  last  pro- 
duct e<iual  tli<^  (luantlJy  discharge  1  iu  cubic  feet  jxr  second. 

2.  Whrnllie  ApiTlurein  witler  (I  (I'lrvn  Ihul.  Multiply  the  area 
of  th(!  aperture  in  feet  by  tli(i  stjuart'  root  of  tlm  depth  also  in 
feet,  and  by  5.1;  the  product  is  the  (quantity  disciiurged  iu  cubic 
feet  per  second. 

ExAMPi.K  1.  Retpiired  the  quantity  of  water  in  cubic  feet  per 
second  diachargod  through  an  opening  in  the  side  of  a  dam  or 


CENTRE    OF    GYRATION.  177 

weir,  the  width  or  length  of  the  opening  being  6^  feet,  and  the 

depth  9  inches,  or  .75  of  a  foot. 

Square  root  of  .75  =  .866. 

rri,      6.5  X  .75  X  .866X5.1X2 

Then ^ =14.3839  cubic  feet. 

Example  2. — What  would  be  the  quantity  discharged  through 
the  above  opening  if  under  a  head  of  water  4  feet  in  height  ? 
Square  root  of  4  =  2 ;  and 
2  X  5.1  =  10.2  feet,  velocity  of  the  water  per  second;  and 
6.5  X  -75  X  2  X  5. 1  =  49.7i5  cu.  ft.  discharged  in  the  same  time. 


THE  CENTRE  OF  GYRATION. 

The  centre  of  gyration  is  that  point  in  any  revolving  body,  or 
system  of  bodies,  that  if  the  whole  quantity  of  matter  were  col- 
lected in  it,  the  angular  velocity  would  be  the  same  ;  i.  e.,  the 
momentum  of  the  body,  or  system  of  bodies,  is  centred  at  this 
point. 


To  Find  the  Centre  of  Gyration. 

Rule  1. — Multiply  the  weight  of  the  several  particles  by  the 
squares  of  their  distances  in  feet  from  the  centre  of  motion,  and 
divide  the  sum  of  the  products  by  the  weight  of  the  whole  mass; 
the  square  root  of  the  quotient  will  be  the  distance  of  the  centre 
of  gyration  from  the  centre  of  motion 

Example. —Suppose  3  weights  of  3  lbs.,  4  lbs.,  and  5  lbs.  re- 
spectively, be  fixed  on  a  lever,  which  is  assumed  to  be  without 
weight,  at  the  respective  distances  of  1,  2,  and  3  feet :  required 
the  distance  of  the  centre  of  gyi-ation  from  the  centre  of  motion. 

3  1bs.Xl''  =  3;  4  1bs.x2i:=16;  and  5  lbs. X  3^  =  45. 

Hence,  „y"T    ^  =  5.33  ;    and    v/'^-33  =  2  3   feet    distance 
3+    4+    5 

from  the  centre  of  motion. 

Therefore,  a  single  weight  of  12  lbs.,  placed   at  2.3  feet  from 

the  centre  of  motion,  and  revolving  in  the  same  time,  would 

have  the   same   impetus  as   the  3  weights   in   their  respective 

places. 

Rule  2. — Multijily  the  distance  of  the  centre  of  oscillation 
from  the  centre  of  the  system,  or  point  of  suspension,  by  the 
distance  of  the  centre  of  gravity  from  the  same  point;  the  square 
root  of  the  product  will  be  the  centre  of  gyration. 

Example. — The  centre  of  gravity  being  4  feet  from  the  point 
of  suspension,  and  that  of  oscillation  9  feet:  required  at  what 
distance  the  centre  of  gyration  is  from  the  point  of  suspension. 
4X9  =  36;  and   ^Z  36  =  G  feet.     Ans. 

Mr.  Farey  has  given  the  following  as  the  distances  of  the  cen- 
tres of  gyration  from  the  centre  of  motion,  in  different  revolving 
bodies. 

8* 


178  CENTRIFUGAL   FORCE. 

In  a  straight  uniform  rod,  revolving  about  1  end,  tlie  length 
of  the  rod  X  by  .5773. 

In  a  circular  plate,  revolving  on  its  centre,  the  radius  of  the 
circle  X  7071. 

In  a  circular  plate,  revolving  about  1  of  its  diameters  as  an 
axis,  the  radius  X  -5. 

In  a  thin  circular  ring,  revolving  aboiit  1  of  its  diameters  as  an. 
axis,  the  radius  X  .7071. 

In  a  solid  sphere,  revolving  about  1  of  its  dianaeters  as  an  axis, 
the  radius  X  .63'25. 

In  a  thin  hollow  sphere,  revolving  about  1  of  its  diameters  as 
an  axis,  the  radius  X  .8104. 

In  a  cone,  revolving  aboiit  its  axis,  the  radius  of  the  circular 
base  X  -5177. 

In  a  rij^ht-an|.;led  cone,  revolving  about  its  vertex,  the  height 
of  the  cone  X  .8GG. 

In  a  paraboloid,  revolving  abotit  its  axis,  the  radius  of  tho 
circular  uase  X  •  5773. 

Note. — The  weight  of  tho  revolving  body,  multiplird  into  tho 
height  duo  to  the  velocity  witli  which  the  centre  of  gyration 
moves  in  its  circle,  is  the  energy  of  the  body,  or  the  mechanical 
power  which  must  be  communicated  to  it  to  give  it  that  motion. 


CENTKIFUGAL  FORCE. 

All  lx>dies  moving  round  a  cu'iitral  point,  have  a  tendency  to 
fly  off  in  a  straight  lino:  this  tendency  is  called  the  centrifugal 
force:  it  is  opposed  to  the  centripetal  force,  or  that  power  which 
maintains  the  bo  ly  in  its  curvilinear  path. 

The  centrifugal  force  of  a  body,  moving  witli  different  veloci- 
ties, in  the  same  circle,  is  proportional  to  tho  sijuaro  of  tho 
velocity,  or  to  tlie  ?(inar(i  of  tlie  number  of  revolutions  perform- 
ed in  a  given  tinu;.  I  lius,  the  centrifugal  force  of  a  body  luaking 
40  revolutions  i)er  minute,  is  4  timers  as  groat  as  the  cc^itrifugal 
force  of  the  samo  body  when  making  20  revolutions  per  minute. 

To  find  the  Centrifugal  Force  of  any  Body. 

Boles. — 1.  Divide  tlie  velocity  in  feet,  per  second,  liy  4.01, 
and  the  s(iuaro  of  tho  (juotient  by  tlio  diametor  of  the  circle;  the 
(piotitait  is  tlio  (vntrifugal  force  wluiii  the  weight  of  tho  body 
is  1.  Hence,  tho  (piotient  multiplied  by  the  weight  of  the  body, 
is  tho  centrifugal  force. 

Example.  lle(juir(nl  tho  centrifugal  force  of  the  rim  of  a  fly- 
whool,  20  foot  in  diameter,  moving  with  the  velocity  32  1-G  feet 
in  u  second. 

32  1-0  —  4.01=8.02; 
8.02--|-2a  =  3.210  times  tho  woiglit  of  tlio  rim. 

2  Multiply  tho  scjuaro  of  tho  number  of  revolutions  in  a 
minute  by  tho  diameter  of  the  circle  in  feet,  and   divide  tho 


PLY-WHEEL.  179 

product  by  the  constant  number  5370;  the  quotient  is  the  centrif- 
ugal force  when  the  weight  of  the  body  is  1.  Hence,  as  in  the 
1st  rule,  the  quotient  multiplied  by  the  weight  of  the  body,  is 
the  centrifugal  force. 

Example. — Required  the  centrifugal  force  of  a  stone,  weighing 
2  lbs.,  revolving  in  a  circle  i  feet  in  diameter,  at  the  rate  of  120 
revolutions  in  a  minute. 

120'  X  -4  =  57600  :  and  ^I^=9.8L 

5870 

Hence,  9.81  X  2  =  19.G2  centrifugal  force. 

Dr.  Brewster  has  summed  up  the  whole  doctrine  of  centrifugal 
forces  in  tlie  following  propositions  : 

1.  The  centrifugal  forces  of  two  unequal  bodies,  moving  with 
the  same  velocity,  and  at  the  same  distance  from  the  central 
body,  are  to  one  another  as  the  respective  quantities  of  matter 
in  the  two  bodies. 

2.  The  centrifugal  forces  of  two  eqiial  bodies,  which  perform 
their  revolutions  round  the  central  body  in  the  same  time,  but 
at  different  distances  from  it,  are  to  one  another  as  their  respec- 
tive distances  from  the  central  body. 

3.  The  centrifugal  forces  of  two  bodies  which  perform  their 
revolutions  in  the  same  time,  and  whose  quantities  of  matter  are 
inversely  as  their  distances  from  the  centre,  are  equal  to  one 
another. 

4.  The  centrifugal  forces  of  two  equal  bodies,  moving  at  equal 
distances  from  the  central  body,  but  with  diflferent  velocities,  are 
to  one  another  as  the  squares  of  their  velocities. 

5.  The  centrifugal  forces  of  two  unequal  bodies,  moving  at 
equal  distances  from  the  centre,  with  different  velocities,  are  to 
one  another  in  the  compound  ratio  of  their  quantities  of  matter, 
and  the  squares  of  their  velocities. 

6.  The  centrifugal  forces  of  two  equal  bodies,  moving  with 
equal  velocities  at  different  distances  from  the  centre,  are  in- 
versely as  their  distances  from  the  centre. 

7.  The  centrifugal  forces  of  two  unequal  bodies,  moving  with 
equal  velocities  at  different  distances  from  the  centre,  are  to  one 
another  as  their  quantities  of  matter  multiplied  by  their  respec- 
tive distances  from  (he  centre. 

8.  The  centrifugal  forces  of  two  unequal  bodies,  moving  with 
unequal  velocities  at  different  distances  from  the  central  body, 
are  in  the  comi^ound  ratio  of  their  quantities  of  matter,  the 
squares  of  their  velocities,  and  their  distances  from  the  centre. 


THE  FLY-WHEEL. 

It  is  an  object  of  great  importance  in  machines  to  have  means 
of  accumulating  power  when  the  moving  force  is  in  excess,  and 
of  expending  it  when  the  moving  force  operates  more  feebly  or 
the  resistance  increases.    This  equalization  of  motion  is  obtained 


ISO  FLY-WHEEL. 

by  what  is  called  the  fly-wheel,  which  is  generally  made  in  the 
form  of  a  heavy  wheel.  The  flj'-wheel  being  made  to  revolve 
about  its  axis,  keeps  np  its  force  by  its  own  inertia,  and  distrib- 
utes it  in  all  parts  of  its  revolution.  Fly-wheels  are  capable  of 
accumulating  power  to  a  great  extent,  and,  when  thus  accumu- 
lated, they  assist  in  bringing  the  crank  past  its  entres,  but  much 
of  their  efficacy  depends  on  the  position  assigned  them  in  the 
machinery.  If  the  tly  is  used  as  a  regulator  of  force,  it  should 
be  placed  near  the  prime  mover;  but  if,  on  the  other  hand,  it  be 
used  as  a  magazine  of  power,  it  should  be  near  the  working 
point.     No  general  rules  can  be  given  for  its  exact  position. 


To  find  the  Weight  of  the  Rim  or  Ring  of  a  Ply- 
Wheel  proper  for  a  Steam-Engine. 

Rule. — Multiply  the  constant  number  13G8  by  the  number  of 
horse-power  that  the  engine  is  ecpial  to  ;  divide  the  product  by 
the  diameter  of  the  wheel  in  feet,  multiplied  by  the  number  of 
revolutions  per  minute,  imd  the  quotient  is  the  weight  of  the 
ring  in  100  pounds  nearly. 

Example. — Required   the   weight  of  the   rim  of  a   fly-wheel 
proper  for  an  engine  of  30  horse-i)o\ver,  the  wheel  to  be  H  feet 
in  diameter,  and  making  40  revolutions  per  minute. 
1:3GSX30      4104)       ..  ,        . 

T4x4ur=-5G(r==^^-^"^- 

Note. — The  fly-wheel  of  an  engine  for  a  flour-mill  ought  to  bo 
of  such  a  diameter  that  the  velocity  of  the  periphery  of  the  wheel 
may  exceed  the  velocity  of  the  periphery  of  the  stones,  to  pre- 
vent, as  much  as  possible,  any  tendency  to  back  lash,  as  it  is 
termed. 

The  necessary  weight  and  diameter  of  the  wheel  being  found, 
suppose  a  breadth  of  a  rim.     Then, 

To  find  the  Thickness  necessary  to  make  the 
Weight  in  Cast  Iron. 

Rule. — Divide  the  required  weight  in  pounds  by  the  area  of 
th(^  ring  in  inches  multiplied  by  .'2G1,  and  the  quotient  is  the 
thickness  of  the  ring  in  inches. 

ExA>fPLE. — ^V^lat  thickness  must  a  ring  of  a  fly-wheel  be  to 
equal  f>4. 1  cwt.,  when  the  outer  diann'ter  is  14  feet  and  the  inner 
diameter  12  feet? 

r.4.1  cwt.  ^WlOlbs. 
Diam.  14  feet  —  108  in.  and  12  ft  =  144  in.,  and  the  area  of  the 

ring  :=  5881  sq.  in. 
„.  r,410  fi-UO        ,  ,„  . 

T^«"'  r,881  xT2iir^l53.50  =  ^-^^^^-  "^'^y* 

Note.— If  the  ring  is  to  bo  of  a  cylindrical  form,  its  diameter 
may  ha  easily  found  bv  the  following  ajjproximate 


FLY-WHEEL,    ETC. 


181 


Rule. — Multiply  the  required  weight  in  jioumls  by  1.62;  di- 
/ide  the  product  by  the  diameter  of  the  wheel  in  inches  and 
the  sqiiare  root  of  the  quotient  will  be  the  diameter  of  the  cross- 
section  of  the  ring  in  inches,  nearly. 


Thus, 


y/  6410  X  iH2 


=  7.7  inches. 


Note. — The  centre  of  percussion  in  a  fly-wheel,  or  wheels  in 
general,  is  |  distant  from  the  centre  of  suspension,  nearly. 

The  centrifugal  force  is  that  power  or  tendency  wlaich  all  revolv- 
ing bodies  have  to  burst  or  Ay  asunder  in  a  direct  line. 

And  the  centre  of  percussion  in  a  revolving  body  is  that  point 
where  the  whole  force  or  motion  is  collected,  or  that  point  which 
would  strike  any  obstacle  with  the  greatest  effect. 


MELTING  POINT  OF  SOLIDS. 


Cast  Iron  melts 

Wr't     " 

Gold 

Silver 

Steel 

Brass 

Copper 

Glass 


DEGREES. 

3,477 

"     3,981 

"     2,587 

"     1,250 

"     2,501 

"     1,897 

"     2,550 

■•'     2,377 


Platinum 

Lead 

Zinc 

Cadmium 

Saltpetre 

Tin 

Sulphur 

Potassium 


DEGREES. 

melts  3,077 

"     600 

"     741 

"     602 

"     600 

"     420 

"     225 

'•     135 


Table  of  Hollow  Cylindrical  Columns,  for  Large 
Mills,  with  Cores. 


Diameter 

\  iaineter 

Diameter 

Diameter 

Length  of 

No.  of  Cu- 

Total 

of  Uolumn 

of  aCros  — 

of  tue  Core 

of  the  Core 

the 

bic  Inches 

Weight  of 

at  small 

Section  in 

at  riuall 

at  the 

Column  in 

in  the 

Column  in 

end. 

the  miJ'le 

end. 

middle. 

Feet 

Column. 

Pounds. 

Inches. 

Inches. 

Inches. 

Inches. 

7 

11 

2 

n 

12 

8,944 

2,236 

8 

12 

2 

4 

12 

10,4(10 

2,600 

9 

14 

3 

n 

14 

13,849 

3,462 

10 

16 

4 

10 

16 

33,744 

8,438 

It  has  been  fully  tested  that  cast  iron  columns  of  a  large  dimen- 
sion witli  a  core  are  much  stronger  than  without  it.  This,  no 
doubt,  arises  from  the  fact  that  the  case  affords  a  sensible  spring 
in  case  of  a  sudden  strain,  and  therefore  less  liable  to  fracture. 


i&3  STEAM   AXD    THE   STEAM-ENGINE. 


STEAM  AND  THE  STEAM-ENGINE. 


Nominal  Power  of  S team-Engines. 

The  usual  estimate  of  the  dynamical  effect  per  minute  of  a 
horse,  called  by  engineers  a  horse-power,  is  33,000  lbs.  at  a 
velocity  of  1  foot  per  minute  ;  or  the  effect  of  a  load  of  200  lbs. 
raised  by  a  horse  for  8  hours  a  day  at  the  rate  of  2^  miles  per 
hour;  or  150  lbs.  at  the  rate  of  220  feet  per  minute. 


To  determine  the  Diameter  of  a  Cylinder  for  an 
Engine  ot  a  required  Nominal  Power. 

Divide  5,50.J  by  the  velocity  of  the  piston  in  feet  per  minute, 
and  the  quotient  equals  the  number  of  square  inches  to  a  horse- 
power, which  multiply  by  the  reejuired  number  of  horse-power, 
and  the  product  is  the  cylinder's  area,  against  which,  in  the 
Table  of  Areas,  is  the  diameter  required. 

Example. — Required  the  diameter  of  the  cylinder  for  a  25- 
horse  engine,  with  a  velocity  of  230  feet  per  minute. 

""^  ^  23.913  X  25  =  597.825  inches  area;  or  27^  inches  diame- 
ter, nearly. 


oportiona 

te  Velocities  for  the  Pistons  of  Stati( 

ary 

Condensing  Engines. 

Length  of  Stroke, 

Velocity  iu  Feet 

Number 

of  Revolutions 

iu  feet. 

per  Miuute. 

pe 

r  Minute. 

8 

256 

16 

7 

245 

17^ 

6 

240 

20 

5i 

23G.', 

211 

5 

230' 

23 

^ 

220.1 

21J 

26! 

4 

21-1" 

3i 

2(J3 

29 

3 

l'.»2 

32 

21 

177i 

35J 

2" 

160 

40 

To  estimate  the  Amount  of  EfTfectivo  Power  of  an 
Engine  by  an  Indicator. 

Multiply  the  area  of  the  piston  in  s(jnare  inches  by  the  aver- 
age force  of  tho  steam  in  lbs.,  and  by  the  velocity  of  the  piston 
in  feet  per  minute  ;  divide  the  ])roduct  by  33,000,  and  7-10  of 
the  quotient  cijunl  the  effective  power. 


STEAM   AND    THE   STEAM-ENGINE.  183 

ExAjrPLE. — Suppose  an  engine,  -with  a  cylinder  of  37 J  inches 
diameter,  a  stroke  of  7  feet,  and  making  17  revolutions  per  min- 
ute, or  238  velocity,  and  the  average  indicated  pressure  of  the 
steam  16.73  lbs.  per  squai-e  inch  :  required  the  effective  power. 
1104.4G87  inches  X  16.73  lbs.  X  233  feet      133.26  X  7 


Axea  =  ' 


3:i000  10 

^93.282  horse-power. 


To  find  the  Greatest   Quantity  of  Water  required. 

for  Steam. 

Multiply  the  area  of  the  cylinder  in  feet  by  the  piston's  ve- 
locity in  feet  per  minute,  add  1-10  for  cooling  and  waste, 
divide  the  sum  by  the  volume  of  steam  compared  to  the  volume 
of  water  (as  per  Table  of  Pressiires),  and  the  quoti.ent  equals  the 
quantity  in  cubic  feet  per  minute. 

Note. — For  single-acting  engines  only  about  half  the  quantity 
is  required. 

Example  — Eequired  the  quantity  of  water  for  steam  to  supply 
an  engine,  whose  cylinder  is  2  feet  diameter,  the  jiiston's  velocity 
214  feet  per  minute,  and  the  pressure  of  steam  18  Ib.s.  per  sqiiare 
inch,  including  the  pressiire  of  the  atmosphere. 

Area=  3.1116x214  =  672.3  +  67.23  =  739.53  ^  1411  =  .523 
cubic  feet  per  minute. 


To  find  the  Quantity  of  Water  required  for 
Injection. 

From  1212  subtract  the  temperature  of  the  condensed  water  ; 
divide  the  result  by  the  temperature  of  the  condensed  water 
minus  the  temjierature  of  the  cold  water  ;  multiply  the  quotient 
by  the  quantity  of  steam  in  cubic  feet  in  a  given  time,  and  the 
product  equals  the  quantity  of  water  in  cubic  inches. 

Example. — Reqiiired  the  quantity  of  water  at  60'^,  to  condense 
50  )  cubic  feet  of  steam  to  water  at  95^  Fahrenheit. 

"^^ Ei  =  31.9  X  500  =  15950  cubic  inches. 

or,  159:>0  X  .00058  =  9.251  cubic  feet. 


Proportions  of  Cylinder,  Condenser,  and  Air-Pump. 

The  length  of  the  cylinder,  and  consequently  the  stroke  of 
the  piston,  ought  not  to  be  less  than  twice  the  cylinder's  diame- 
ter ;  as  then  the  least  surface  is  exposed  in  proportion  to  the 
capacity  :  and  the  longer  the  stroke,  the  greater  the  effect,  from 
the  principle  of  expansive  force. 

The  capacities  of  the  condenser  and  air-pump  are  each  \  the 
capacity  of  the  cylinder. 


1S4 


STEAM  AND   THE  STEAM-ENGINE. 


Advantages  derived,  from  the  Expansive  Properties 

of  Steam. 

If  stoain  of  a  uniform  elastic  force  be  employed  throughout  the 
■vs'liole  ascent  or  descent  of  the  piston  of  a  steam-engine,  the 
a:u  >unt  of  effect  is  as  the  quantity  expended.  Biat  suppose  the 
steam  to  be  shut  off  at  any  portion  of  the  stroke,  say,  for  in- 
stance, at  one-half,  it  expands  by  degrees  until  the  termination 
of  tie  stroke,  and  then  exerts  half  its  original  force  ;  lience  an 
accumulation  of  effect  in  proportion  to  the  quantity  of  steam. 


To  obtain  or  calculate  the  Amount  of  Effect. 

Divide  the  length  of  the  stroke  by  the  length  of  the  space  into 
which  the  dense  steam  is  admitted,  and  find  the  hyperbolic 
logarithm  of  the  quotient,  to  which  add  1,  and  the  sum  is  the 
ratio  of  the  gain. 

Example. — Suppose  an  engine  with  a  stroke  of  G  feet,  and  the 
steam  cut  off  when  the  piston  has  moved  through  2  :  required 
the  ratio  of  iiniform  elastic  force. 

G^2  =  3;  hyperbolic  logarithm  of  3  =  1.0986  +  1=2.0986, 
ratio  of  effect;  that  is,  supposing  the  whole  effect  of  the  steam  to 
be  3,  the  effect  by  the  steam  being  cut  off  at  J  =  2.0986. 


Table  of  Hyperbolic  Logarithms. 


Ko. 


Logarithm, 

No. 
3.V 

.22314 

.40546 

n 

.559G1 

4' 

.G9314 

i\ 

.81093 

4.1 

.91G29 

n 

l.OllGO 

5 

•1.098G1 

5V 

1.178C5 

5i 

Logarithm. 

No. 

5} 

1.25276 

1.32175 

6 

1.38G29 

6} 

1.44G91 

4 

1.50507 

1.55814 

7 

1.G0943 

7.} 

1.G3822 

7.V 

1.70474 

n 

Logarithm. 

No. 

i 

8 

1.74919 

1.79175 

8.\ 

1.83258 

9" 

1.87180 

9.! 

1.90954 

10" 

1.94591 

12 

1.98100 

14 

2.01490 

IG 

2.047G9 

18 

Logar'm. 

2.07944 
2.14006 
2.19722 
2.25129 
2.30258 
2.48490 
2.G3905 
2.77258 
2.89037 


LOCOMOTIVE  ENGINE!. 

Tabic  showing  the  Circumforonces  of  different 
Driving  Wheels. 


l^iam.  of  Wheel. 

J.<-n^tli  of  (  iriuiii. 

Diam.  of  Wheel. 

Lougth  of  Circum. 

ft.       in. 

feet. 

ft.      iu. 

foot. 

4       0 

12.5GG 

6      G 

20.419 

4      G 

13.927 

7      0 

21.990 

5      0 

r..7()7 

7      G 

23.5G1 

5      G 

17.278 

8      0 

25.132 

G      0 

1;h.849           I 

STEAM  AND   THE  STEAM-ENGINE. 


185 


Table  containing  the  Velocity  of  the  Pistons,  that 
of  the  Circumference  of  the  Driving  Wheels  being 
taken  as  1. 


ID    9    B 

o  **  c 
-•■si 


in, 
23 
19 
18 
17 
16 
15 
14 
11 
12 


Diameters  of  Driving  Wheels. 


4ft.  Oin. 
0.2652 
0.2519 
0.2386 
0.2254 
0.2121 
0.1989 
0.1856 
0.1724 
0.1591 


4ft.  Gin. 
0.2393 
0.2273 
0.2153 
0.2034 
0.1914 
0.1795 
0.1675 
0.1555 
0.1436 


5ft.  Oin. 

0.2122 

0.2016 

0.1910 

0.1803! 

0.1697 

0.1591 

0.148") 

0.1379 

0.1273! 


5ft.6in. 
0.1929 
0.1832 
0.1736 
0.1640 
0.1543 
0.1447 
0.1350' 
0.1254 
0.1157 


6ft.  Oin. 
0.1768 
0.1679 
0.1591 
0.1503 
0.1415 
0.1326 
0.1237 
0.1149 
0.1061 


6ft.  6in. 
0.1632 
0.1550 
0.1468 
0.1387 
0.1305 
0-1224 
0.1141 
0.1061 
0.0979 


7ft.  Oin 

0.1516 

0.1440 

0.1364 

0.1288 

0.1213 

0.1137 

0.1061 

0.09S^5 

0.0909 


7ft.  6in. 
0.1414 
0.1343 
0.1272 
0.1202 
0.1131 
0.1060 
0.0990 
0.0919 
0.0848 


8ft.  Oin. 
0.1326 
0.1259 
0.1194 
0.1127 
0.1061 
0.0994 
0.0928 
0.0862 
0.0796 


Application  of  this  Table  for  finding  the  Tractive 
Power  of  Locomotive  Engines. 

Multiply  the  sum  of  the  areas  of  the  two  pistons  by  the  effec- 
tive pressure  of  the  steam  in  i^ounds,  and  further,  that  product  by 
the  co-eflicient  in  the  table  (belonging  to  its  driving  wheels  and 
stroke  of  the  pistons),  and  this  new  product  will  be  the  traction 
of  the  engine  in  pounds. 

Example. — A  locomotive  engine  to  have  5  feet  6  inch  driving 
wheels,  cylinders  of  13  inches  diameterby  18  inches  stroke,  and 
the  effective  pressure  of  the  steam  to  be  40  lbs.  on  the  square 
inch :  what  is  its  traction  ? 

(2  X  132.66)40  X  0-1736 

1842.39  lbs.  of  traction. 

If  it  be  required  to  know  the  number  of  tons  the  engine  is  able 
to  draw  on  a  level,  divide  its  traction  by  the  friction  in  pounds. 

If  the  engine  is  to  go  up  inclines,  then  add  to  that  friction  the 
gravity  in  pounds  due  to  a  ton  on  that  incline,  and  use  this  sum 
as  a  divisor  for  the  traction,  the  quotient  will  be  the  number  of 
tons  the  engine  is  capable  to  rise  up  that  incline  with.  In  both 
cases  is  the  weight  of  the  engine  and  its  tender  in  the  quotient 
included. 

Explanations. — By  effective  pressure  is  understood  the  pressure 
of  the  steam  above  the  pressure  of  the  atmosphere,  less  the  num- 
ber of  pounds  necessary  to  keep  the  engine  by  itself  just  in 
motion. 

Frid'ion,  the  power  necessary  to  move  a  mass  along,  which  is 
generally  taken  to  be  on  railroads  equal  to  10  lbs.  for  every  ton. 

Gravity,  the  power  to  overcome  the  tendency  of  a  mass  or  load 
to  descend  an  incline,  being  always  equal  to  the  quotient  of  the 


186  STEAM  AND   THE  STEAM-ENGINE. 

product  of  the  load  and  height  of  the  incline,  divided  by  the 
length  of  the  incline. 

Therefore  the  above  engine  would  draw 

1842.39 

— r^^ — =  Ibi  tons  on  a  level; 

and  on  an  inclined  plane,  say  as  1  in  300. 

Friction  =  10  lbs. 

«"'*y  =  lJ<|l»=7.,CGlta. 

17.466  lbs. 

,,    1842.39      ,«^  ^  , 
Consequently        ^^^  =105.5  tons  up  an  incline  of  1  in  SOO. 

If  the  weight  of  the  engine  with  its  tender  bo  taken  at  18  tons 
it  will  draw  a  net  gross  load  of 

166  tons  on  a  level,  and 
87.5  tons  up  an  incline  of  1  in  300. 


To  calculate  for  the  Travel  of  the  Valves,  ThroTir 
of  Eccentrics,  &c. 

Example. — Suppose,  in  a  locomotive  engine,  the  valves  require 
a  travel  of  3^  inches;  the  top  lever,  or  lever  immediately  connect- 
ed with  the  valve  spindle,  being  9.\  inches,  and  the  bottom  lever 
8  inches:  what  must  be  the  throw  of  eccentrics  ? 

^•'[^^^  =  3.243  inches,  or  31,  nearly. 

Note. — The  travel  of  a  valve  equals  the  width  of  the  two  steam 
openings,  plus  the  lap  of  the  valve  over  each  oi)cning;  and  the 
whole  length  of  its  movement  or  face  ujx)!!  the  cylinder  equals 
twice  the  travel  of  the  valve,  jjIus  the  distance  between  the  two 
steam  openings. 


To  ascertain  the  Amount  of  Weight  or  Pressure  on 
the  Safety-Valve  of  a  Locomotive  Engine. 

Divide  the  length  of  the  lever  by  ilio  distance  from  its  centre 
of  motion  to  centre  of  valve,  and  multiply  the  iudi(!at(Ml  pressure 
on  the  sjjring  lialance  by  the  quotient,  to  whieli  add  the  action 
or  pressure  of  the  levf^r  and  spring  balanci';  divide  the  sum  by 
tlie  area  of  the  valve,  and  the  quotient  equals  the  pressure  on 
each  inch  of  tin;  boiler. 

E.VAMPI.K.  —  Sujiposo  an  engine  with  valve  levers  of  22j  inches 
in  lengtli,  and  the  distance  from  the  ]iin  to  centre  of  valve  2J 
iiielies;  th(^  action  of  the  lover  aiul  si>riiig  balance  5  lbs. ;  the  in- 
dicated ])ressuni  50  lbs.,  imd  tlie  area  of  the  valve  7  inches:  re- 
quired tlie  pressure  on  each  sipiare  incdi. 

22.5-1-2.5  =  9  ;  aud^^-^JJ-^  =  65  lbs.  per  square  inch. 


STEAM   AND   THE   STEAM-ENGINE. 


187 


To  determine  the  Pressxire  of  Steam  equal  to  the  re- 
sistance of  a  given  load,  by  a  Locomotive  Engine. 

It  is  ascertained,  by  exiieriment,  that  6  lbs.  per  ton  of  tho 
engine's  weight  is  expended  in  overcoming  the  friction  of  its 
l^arts  when  unloaded;  9  lbs.  per  ton  of  gross  load  for  horizontal 
traction  and  additional  friction  caused  by  the  load;  and  14.7 
lbs.  per  square  inch,  the  pressure  of  the  atmosphere.  Hence,  to 
9  times  the  gross  load  of  the  train  in  tons,  add  the  friction  of 
the  engine  ;  multiply  the  sum  by  the  diameter  of  the  driving 
wheels  in  inches;  divide  tho  jiroduct  by  the  cylinder's  capacity 
in  inches,  and  the  quotient,  plus  14.7,  equals  the  pressure  of  the 
steam  in  lbs.  per  square  inch  on  the  piston. 

.Ex.\MPiiE. — Required  the  pressure  per  square  inch  on  the  pis- 
ton's area,  to  overcome  a  loa-t  of  120  tons  gross  on  a  level  line, 
the  engine  being  13  tons,  driving  wheels  5^  feet,  cylinders  13 
inches  diameter,  and  length  18. 

120  — 13  =  107  X  9  =^  1080;  and  13  X  6  =  78,  the  force  of  traction; 

13- X  18  =  3042. 
rj^^^  1080  +  78  X  66  . 

3042 


:  25.12  +  14.7  =  39.82  lbs.  per  sq.  inch. 


Table  of  the  Areas  of  Cylinders  from  9  to  15  Inches 

Diameter. 


Diam.  of  Cylinder- 

Area  of  Cylinder. 

Diam.  of  Cylinder. 

AreaofC^'linder. 

Inches. 

Siiuare  Inches. 

Inches. 

Square  Inches. 

9 

G3.5S 

12^ 

122.65 

10 

78.5 

13 

132,.  66 

101 

86.56 

13^ 

143.02 

11 

95.01 

14 

153.96 

lU 

103.84 

^^ 

165.04 

12 

113.07 

15 

176.62 

Note. 
eters. 


-The  areas  of  cylinders  are  as  the  squares  of  their  diam- 


Various  modifications  have  lately  been  added  to  the  list  of  im- 
provements in  locomotive  engines,  and  among  the  most  efficient 
is  that  of  using  steam  more  or  less  expansively,  as  required. 
The  arrangement  is  such,  that  the  quantity  of  steam,  of  uniform 
density,  is  immediately  changed  to  suit  either  the  load  or  incli- 
nations of  the  line. 

Another  essential  improvement  is  that  of  insuring  a  unifornj 
equilibrium  of  the  engine,  in  case  of  fracture  in  the  front  axle; 
siich  an  occiirrence  being  the  only  real  cause  of  fear  in  running  a 
six-wheeled  engine. 


Ib8 


STEAM   AND   THE   STEAM-ENGINE. 


Table  of  Dimensions  of  the  Principal  Parts  of  Loco- 
motive Engines. 


POBTIONS   OF  THE   ENGINES. 


Oylinders  and  sienm  passages. 

Diameters  of  cylinders 

Distance  from  cen.  to  cen.  of  do. 

Length  of  stroke   

"         steam  and  eduction 
ports   

Width  of  steam  ports 

"  eduction  ports 

Breadth  of  bridges  betw.  ports 
Cylindrical  paH  of  the  boiler  and  tubes. 

Diameter  of  the  boiler 

Length         "  "     

"  "       tubes 

Diameter     "  "     

Thickness  of  tubes  bywire  gauge 

Number  of  the  tubes 

Inside  and  outside  fire  boxes. 

Length  of  inside  fire  box 

Breadth         "  "        

Height  above  the  fire  bars 

Area  of  fire  grate 

Length  of  outside  fire  box 

Breadth  "  "      

Thickness  of  plates 

Ex.  thick,  where  tubes  inserted. 
.Sy/to/.-e  box,  cJiimney,  ami  blast  pipe. 

Length  of  smoke  box,  inside.  . . 

Breadth  "  " 

Thickness  of  plates 

Diameter  of  chimney 

Height  to  top  of  do.' from  rails. 

Diameter  of  blast  pipe 

WliPiis,  .vprini/s.  d'c. 

Diameter  of  driving  wheels  .... 
"              hading       *'       ... 
"  fniiliiig      "       

Breadth  of  tires 

Thickness,  average 

Diameter,  of  axlo  bearings 

Length  "  "  ... 

"  driving-whc(!l  springs. 

Breadth  of  "  "       . 


GAUGE   OF 

RjOLWAY. 

4  Ft.  8  >i  In- 

6  Feet. 

7  Feet. 

ft. 

ins, 

ft. 

ins. 

ft 

ins. 

1 

1 

1 

2 

1 

3 

2 

5 

2 

5 

3 

0 

1 

6 

1 

6 

1 

8 

0 

11 

0 

11 

0 

lU 

0 

1.1 

0 

n 

0 

u 

0 

o| 

0 

2i 

0 

2| 

0 

0 

o§ 

0 

o| 

3 

4 

3 

7 

4 

0 

8 

0 

8 

6 

8 

6 

8 

5 

8 

11 

9 

0 

0 

2 

0 

2 

0 

2 

No 

14 

No 

14 

No 

14 

121 

131 

137 

3 

0 

3 

4 

3 

8^ 

3 

7 

3 

5 

3 

11 

3 

10 

3 

10 

3 

11 

10 

9 

11 

4 

14 

8 

3 

6 

3 

10 

4 

3 

4 

1 

4 

0 

4 

6 

0 

o! 

0 

03 

0 

^ 

0 

0 

01 

0 

o| 

2 

1 

2 

1 

2 

2 

4 

2 

4 

21 

5 

0 

^ 

0 

0 

0 

0 

1 

1, 

1 

2 

1 

4 

13 

4 

13 

G 

14 

10 

0 

31 

0 

3.1 

0 

3| 

5 

r, 

(\ 

0 

7 

0 

4 

0 

4 

0 

4 

0 

3 

f. 

4 

0 

4 

0 

0 

ry\ 

0 

r>), 

0 

5, 

0 

1] 

0 

]! 

0 

1; 

0 

3i 

0 

3- 

0 

4 

0 

f!3 

0 

(',■ 

0 

7 

2 

9 

2 

9 

2 

G 

0 

a;. 

0 

3i 

0 

3i 

BTEAM   AND  THE   STEAM-ENGINE. 


189 


POBTIONS   OF   THE   ENGINES. 


iVheds,  springs,  cf'c 

Number  of  plutes 

Length  of  leading  wheel-spring's 
±>readth  of      " 

Kumber  of  plates ( 

Trailing-wheel  springs. 

Breadth  of  do. 

Number  of  plates i 

Diameter  of  safet.y  valves  

"  piston  rods 

"  valve  spindles  .  . . 

"  crank  pins 

"  pump  rams 

Extreme  breadth  of  outside  frame 
"       length 


GAUGE    or   KAILWAT. 


4  Ft.  8'^  In.      5  Feet, 


ft. 


1  at  I  and 

12  at  5  5-16 

2      5 

0      3^ 

i  at  I  and 


14  at 

2 

0 
1  at  f  and 
6  at  5-16 

0       3.1 


31 


0 
0 
0 
0 
6 
18 


2 
H 

2' 
5 

^ 


ft. 


7  Feet. 


14  at  55-161 

2 

5 

0 

^ 

1  at 

fand 

14  a 

t  5-16 

2 

2 

0 

3^ 

1  at 

land 

6  at  5-16  1 

0 

Sh 

0  21-161 

0 

U 

0 

5-1 

0 

2 

6 

8^ 

18 

^ 

ft.      iug. 

2  at  I  and 

10  at  5-16 

2      3 

0      3i 

2  at  I  and 

10  at  5-16 

2      3 

0      3} 

2  at  I  and 

8  at  5-1 6 

0      4 


0 
0 

0 

0 

8 

20 


2} 

n 

21 

91 
4 


Table  showing  tho  Approximate  of  Useful  Effect  of 
an  Ordinai'y  Locomotive  Engine  at  different  Velo- 
cities. 


Load  in  Tons. 

Miles  per  hour. 

Miles  pT  hour. 

Load  in  Tons. 

25 

30.90 

10 

250 

50 

25.15 

12^ 

184 

75 

22.54 

15 

138 

100 

18.18 

17^ 

106 

125 

15.98 

20 

83 

150 

14.29 

221 

65 

175 

13.28 

25 

50 

200 

11.20 

27^ 

38 

225 

10.77 

30 

28 

The  increased  resistance  to  traction  on  ascending  inclined 
planes  is  as  the  increased  gravity  of  the  load,  caused  by  the  in- 
clination of  the  plane  ;  or  as  the  length  of  the  plane  to  the  per- 
pendicular height.  Hence,  divide  2,240  (or  the  niiraber  of  lbs.  in 
a  ton)  by  the  inclination  of  the  plane  to  1  or  unity,  to  the  quo- 
tient of  which  add  9,  and  the  sum  equals  the  total  resistance,  in 
lbs.,  per  ton  upon  the  plane. 


190 


STEAM   AND    THE    STEAM-ENGINE. 


Example.  — Required  the  resistance  to  traction,  per  ton,  on  an 
inclined  railway  rising  1  in  300. 

^  =  7.47  +  9  =  16.47  lbs.  per  ton. 


Usefnl  effect  of  a  single-acting  i^nrnping  engine,  with  a  con- 
sumption of  1  bushel  of  coals: 

Diameter  of  cylinder,  5  feet,  3  inches. 

Length  of  stroke,         7     "     9 

Stroke  of  pump,  G     '«     9 

Number  of  strokes  per  minute,  6.1. 

Effective  pressure,  per  square  inch,  of  piston,  13.4  lbs. 

"Water  lifted  1  foot  high,  per  minute,  38,063,288  lbs. 


Table 


Showing  the  Number  of  Revolutions  of  the  Dbtvino  Wheels, 
OR  Strokes  of  the  Piston,  pkr  Minute,  while  the  Engine  is 

PERFOBMINQ  A  KNOWN  NUMBER  OF  MiLES  PER  HoUR. 


Dlam.  of 

Wheel 

4  ft. 


Diam.  of 

Wheel    I    Wheel 
4  ft.  (  lD.I      Sft. 


Diain.  of  DUm.  of  Diam.  of 
Wlieel  Wheel 
ft.  G  In.        6  It. 


No.  of 
revol.  or 
Btrukea 
per  mln. 


No.  of 
rcvol.  or 
BCrokea 
permin. 


280. 
315. 
330. 
3H5. 
420. 
455. 
490, 
52.x 

5or». 

595. 
G30. 
G65 
700. 


31 
63 
94 
126 
157, 
189. 
21|221. 
24  252, 
27284 
30315, 
33  347, 
36  379, 
39  416 
42  442 
45  473. 
48  505 
51  536. 
54  568. 
57  600. 
60  031. 


.59  28. 
,17  56. 
,76  84 
,36112. 
95140. 
54  168. 
13  196. 
72  224. 
30  252. 
90  280 
49  308. 
08  336. 
67  364 
19  392 
85  420. 
r>0  4 18. 
89  477. 
60  504. 
19  532. 
7B  560. 


031  25. 
06;  50. 
09,  76. 
12  101. 
20  127. 
18  152. 
21 177. 
24  203. 
27  229. 
30  254. 
3.1  28). 
36  305. 
39  331. 
42  356. 

50  372 
48  407. 
01  432. 

51  458. 
57  483. 

63  509. 

I 


47  23 
95  46 
42  70 
70  93, 
37  116 
85  140, 
29  163, 
76,U6, 
23  210 
75  233 
17  256, 
64  280, 
11  303, 
58  326, 
05  350, 
60  373, 
99  396. 
55  420. 
93  443, 
50  466. 


DiAm.  of    DlAm.  of 
Wheel    I    Wh-,el 
6  ft.  6  !n.|       7  ft. 

No.  of  I  No.  of 
revol.  or  revol.  or 
strokes  I  strokes 
permin.  I  per  niin. 


34  21.55 
68  43.10 


64.65 
86.20 
70107.75 
04  129.30 
38  150.85 
72|l72.40 
06  19.3.95 
.40215.50 
74  237.05 
08  258.60 
42  280  15 
76  301.70 
10  323.21 
44  311  80 
78  366. 35 
12.387.90 
46  409.45; 
80  431.00 


20 
40 
60 
80 
100 
120 
140 
160 
180 
200 
220 
240 
260 
280 
300 
320 
340 
360 
380 
400 


DIam.  of.  Dl;tm.uf 
Wheel    I    Wheel 
7  ft,  6  in.       6  ft. 


No.  of 
revol.  or 
strokes 
permin. 


No.  of 
revol.  or 
strokes 
p«rmlD. 


17 
35, 
52 
75. 

87, 


18.67 

37.34 

56.01 

74.68 

93  35 
112.02105 
130.69  122 
149.36140. 
168.03157 
186.70175, 
205.37192. 

224.04  210 
242.71227. 

261.38  245 

280.05  262 
298. 72  280, 

317.39  297. 

336.06  315 
).U.73  332. 

373.40  350, 


ES.S. 


5 
10 
15 
20 
25 
30 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
90 
95 
100 


Note.  -To  find  the  velocity  the  piston  is  travelling  at  in  feet 
per  minute,  multiply  tlie  number  of  rfvolntions  of  its  driving 
whccK  in  the  tablo,  l)y  twice  the  longtli  of  its  stroke  in  foet. 


STEAM   AND   THE   STEAM-ENGINE.  191 

Example. — "What  is  the  speed  of  the  piston  of  an  engine  with 
6  feet  driving  wheels  and  15-inch  stroke,  when  going  at  the  rate 
of  50  miles  an  hour? 

By  means  of  the  table  : 

233.4  revolutions  X  ("^^^  =583.5  feet  per  minute. 

The  number  of  revolutions  of  driving  wheels  are  inversely  as 
their  diameters,  and  in  direct  proportion  to  the  number  of  miles 
performed. 

Example.  —How  many  revolutions  have  the  driving  wheels  of 
an  engine  to  make  when  it  is  going  at  95  miles  an  hour,  their 
diameter  being  9  feet  6  inches  ? 

According  to  the  table,  a  4-foot  wheel  would  have  to  make 
665.57  revolutions,  therefore 

9.5:4  ::  665.57:4x665.57      „„,, 

- — — - —  =  280  revolutions, 
y.  0 

The  driving  wheels  of  an  engine  make  35.03  revolutions  when 
going  at  the  rate  of  5  niiles  an  hour,  how  many  will  they  make 
when  going  at  9  miles  ? 

—^ —  =63.05  revolutions. 


To  compute  the  Pressiire  of  Steam. 

When  the  Height  of  the  Column  of  Mercury  it  will  Support  is  given. 

RtTLE. — Divide  the  height  of  the  column  of  mercury  in  inches 
by  2.0376,  and  the  quotient  will  give  the  pressure  per  square 
inch  in  pounds. 

Example.  — The  height  of  a  column  of  mercury  is  203. 76  inches ; 
what  pressure  per  square  inch  will  it  contain  ? 

203.76-^2.0376  =  100  lbs. 


To  compute  the  Temperature  of  Steam. 

RrLE.^Multipl}'  the  Gth  root  of  its  force  in  inches  of  mercury 
by  177,  and  subtract  100  from  the  product,  the  remainder  will 
give  the  temperature  in  degrees. 

Example. — When  the  elastic  force  of  steam  is  equal  to  a 
pressure  of  49  inches  of  mercury,  what  is  its  '^emperature  ? 

Note.  — To  extract  the  6th  root  of  a  number,  ascertain  the  cube 
root  of  its  square  root. 

y  of  49  =  7,  and  3  ^/  of  7  =  1.9129. 

Hence  1.9129  X  177  — 100  =  238=. 58. 


192  STEAM    AND    THE   STEAM-ENGINE. 

To  eomputa  tho  Pressure  of  Steam  in  Inches  cf 

Mercury. 

WJien  the  Temperature  is  given. 

RtTLE. — Add  100  to  the  temperatiire,  divide  the  sum  by  177, 
and  the  6th  power  of  the  quotient  will  give  the  pressure  in  iaches 
of  mercury. 

Example.  — The  temperature  of  steam   is  312°;  what  is    its 

pressure  ? 

100  +  312  ^  2.3277,  and  2.3277«  =  159  ins. 
177 
Note. — To  involve  the  Gth  power  of  a  number,  square  its  cube. 


To  compute  the  Specific  Gravity  of  Steam  com- 
pared with  Air. 

Rule.— Divide  the  constant  number  830.11  (1700  X. 4883)  by 
the  volume  of  tlie  steam  at  the  temperature  of  pressure  at  which 
the  gravity  is  required. 

Example. — The  pressure  of  steam  is  GO  lbs.,  and  the  volume  of 
it  is  470;  what  is  its  specific  gravity  ? 

830.11  +  470  =  1.766. 
Note. — The  specific  gravity  of  steam   compared  with   water 

=  .00058823. 


SLIDE    VALVES. 

/Ill  Diineiisions  in  Inches. 

To  compute  how  much  Lap  must  be  given  on  the 
Steam  Side  of  a  Slide  Valve,  to  cut  off  the  Steam 
at  any  given  Part  of  the  Stroke  of  the  Piston. 

Kiirj:.  Fm)Iu  tin;  Icii^^th  of  strolui  of  ]iist<>n  sulitnict  the  h>ngth 
of  the  stroke  that  is  to  he;  iiiailc!  l)cf'ori!  tlii>  stt'iun  is  imt  oft';  di- 
vide the  r(^in;iiiidiT  by  till' Ktrol<(^  of  thi- ])iston,  and  extract  the 
square  root  of  the  quotiiiil.  Multiply  this  root  bylialf  the  tlirow 
of  the  valve,  from  the  ]irodnct  subtract  half  the  lead,  and  the  re- 
mainder will  give  the  laji  re(piired. 

ExAMPi.K.  Having  stroke  of  piston  60  ins.,  stroke  of  valve  16 
ins.,  laj)  iipou  exhaust  side  },  in.  -  X-'.Vl  of  \i\\\v.  stroke,  lup  uj)on 
steam  siile  3,J  ins.,  lead  2  ins.,  steam  to  be  cut  off  at  5-6  the 
Htroke;  what  is  the  lap? 

60— -of  60  =  10.     '.'*      .166.      ^/.166r=.408.    .408x^^-^3.264, 
6  60  2 

2 

and  3.264  —  -  =  2.264  ins.  or  the  laj)     half  the  h«id. 

u 


STEAM   AND   THE   STBaM-KNGINE.  193 

To  compute  the  Lap  required  on  the  Steam  Side  of 

a  Valve,  to  cut  the  Steam  off  at  various  Portions 

of  the  Stroke  of  the  Piston. 

Value  wUhout  Lead. 

Distance  of  tlie  pistou  from  the  end  of  its  strolie  when  the 
steam  is  cut  oil',  in  pans  of  the  length  of  its  strolie. 

1  -S_  i  7  1  5,  1  1  1_  1 

3  13  3  85         4  5i  IT  8  T3        !J5 

ofTheXoke!  -354  .3'23  .286   .27   .25   .228  .204  .177  144  .102 

Illustkation.  — Take  the  elements  of  the  preceding  case. 
Under  1-6  is  .204,  and  .204  X  10  =  3.2G4  ins.  lap. 

When  the  Valve  is  to  have  Lead. — Subtract  half  the  proposed  lead 
from  the  lap  ascertained  by  tne  table,  and  the  remainder  will  be 
the  proper  lap  to  give  to  the  valve. 

If,  therefore,  as  in  the  last  case,  the  valve  was  to  have  2  ins. 
lead,  then  3.264  —  2  -j-  2  =  2.264  ins. 


To  compute  at  what  Part  of  the  Stroke  of  the  Pis- 
ton any  given  Lap  on  the  Steam  Side  will  cut  off 
the  Steam. 

KuLE.— To  the  lap  on  the  steam  side  add  the  lead ;  divide  the  sum 
by  half  the  length  of  throw  of  the  valve.  From  a  table  of  natural 
smes  find  the  arc,  the  sine  of  which  is  equal  to  the  quotient;  to 
this  arc  add  90°,  and  from  their  sum  subtract  the  arc,  the  cosine 
of  which  is  equal  to  the  lap  on  the  steam  side,  divided  by  half 
the  throw  of  the  valve.  Find  the  cosine  of  the  remaining  arc, 
add  1  to  It,  and  multiply  the  sum  by  half  the  stroke  of  the  pis- 
ton, and  the  product  wuU  give  the  length  of  that  part  of  the 
stroke  that  will  be  made  by  the  piston  before  the  steam  is  cut  oflf. 

Example.  - -Take  the  elements  of  the  preceding  case. 

;„  To  =-5312.5;  sin.  .53125  =  32°  5';  32° 5 -f  90°  =  122°  5'; 

It)  —^  £i 

2. 25 -I- 8  =  .28125  =  cos.  of  73°  40';  then  122°  5'  — 73°  40' =  48°  25; 
cos.  +  1  =  1.66371,  which  X  —  =  50  ins.,  or  5-6  stroke. 


To  compute  the  Distance  of  a  Piston  from  the  End 
of  its  Stroke,  when  the  Lead  produces  its  Effect. 

BuLE.— Divide  the  lead  by  the  width  of  the  steam  port,  both 
in  inches,  and  term  the  quotient  sine;  multiply  its  correspond- 
ing versed  sine  by  half  the  stroke,  and  the  product  will  give  the 
distance  of  the  piston  from  the  end  of  its  stroke,  when  steam  is 
admitted  for  the  return  stroke  and  exhaustion  ceases. 
9 


191 


STEAM  AND   THE   STfiAM-ENGINE. 


Example.     The  stroke  of  a  piston  is  48  ins.,  wultli  of  port 
2\  ins.,  and  the  lead  i  in.;  what  will  be  the  distance  of  the  piston 
from  the  end  of  its  stroke  when  exhaustion  commences? 
.5-^2.5:=.2  =  sino,  and  versed  sine  of  .2  =  .U202. 

Then  .0202  X  ~  =  .4848  ins. 
2 


To  compute  the  Lead,  when  the  Distance  of  a  Piston 
from  the  End  of  its  Stroke  is  given. 

Rule. — Divide  the  distance   in  inches  by  half  the  stroke  ia 
inches,  and  term   the  quotient  versed  sine;    multijjly  the  cor-- 
responding  sine  by  the  width  of  the  steam  port,  and  the  product 
will  give  the  lead. 
Example.  — Take  the  elements  of  the  preceding  case. 
.4848— -24  =  .0202  =  versed  sine, 
and  sine  of  versed  sine  .0202  =  .2.     Then  .2  X  2.5  =  .5  inches. 


To  compute  tho  Distance  of  a  Piston  from  the  End  of 
its  Stroke,  when  Steam  is  admitted  for  its  return 
Stroke. 

Rule. — Divide  the  width  of  the  steam  port,  and  also  that  width 
less  the  lead,  by  half  the  stroke  of  the  slide,  and  term  the  quo- 
tient versed  sines  first  and  second.  Ascertain  tlieir  correspond- 
ing arcs,  and  multiply  tlie  versed  sine  of  the  difference  between 
the  first  and  second  by  half  the  stroke,  and  the  product  will  give 
the  distance  required. 


Portion  of  the  Stroke  of  a  Piston  at  which  the  Ex- 
hausting Port  is  closed  and  opened. 

Lap  on  the  Kclumsl  Side  of  (he  ['aloe  in  Parts  of  Us  Throw. 


Portion  of  Stroke  at  which  the  Steam  is  cut  ofif. 

Lap. 

i 

7 

•i  I 

X 

■I 

1 
t'l 

1 

8 

1 

1  u 

h 

A 

f 

.178 

.101 

.143 

.126 

.109 

.093 

.074 

.053 

1 
1  li 

.13 

.lis 

.1 

.0X5 

.071 

.058 

.013 

.027 

•  ^•» 

.113 

.11(1 

.085 

.0(5!) 

.053 

.043 

.033 

.024 

0 

.002 

.082 

.067 

.055 

.041 

.033 

.022 

.Oil 

B 

h 

.033 

.020 

.019 

.012 

.008 

.004 

.001 

.001 

^^r 

.00 

.052 

.04 

,03 

.022 

.015 

.008 

.002 

■»% 

.073 

.000 

.051 

.012 

.033 

.023 

.013 

.004 

0 

.002 

.082 

.067 

.055 

.044 

.033 

.022 

.011 

STEAM   AND    THE   STEAM-EXGINE.  195 

The  units  in  the  columns  of  the  table  marked  A  express  the 
distance  of  the  piston,  in  parts  of  its  stroke,  from  the  end  of  the 
stroke  when  the  exhaust  port  in  advance  of  it  is  closed  ;  and 
those  in  the  columns  of  the  table  marked  B  express  the  distance 
of  the  piston,  in  parts  of  its  stroke,  from  the  end  of  its  stroke 
when  the  exhaust  port  behind  it  is  opened. 

Illustkation.— A  slide  valve  is  to  cut  off  at  1-6  from  the  end  of 
the  stroke  of  the  piston,  the  lap  on  the  exhaust  side  is  1-32  of 
the  stroke  of  the  valve  (1(3  ins.  „  and  the  stroke  of  the  piston  is 
60  inches.  At  what  point  of  the  stroke  of  the  piston  will  the 
exhaust  port  in  advance  of  it  be  closed,  and  the  one  behind  it 
opened  ? 

Under  1-6  in  table  A,  opposite  to  1-32,  is  .053,  which  X  60,  the 
length  of  the  stroke,  =  3.18  ins. ;  and  under  1-6  in  table  B,  oppo- 
site to  1-32,  is  .033,  which  X  60  =  1.98  inches. 

If  the  lap  on  the  exhaust  side  of  this  valve  was  increased,  the 
effect  would  be  to  cause  the  port  in  advance  of  the  valve  to  be 
closed  sooner,  and  the  port  behind  it  oj^ened  later.  And  if  the 
lap  on  the  exhaust  side  was  removed  entirely,  the  j^ort  in  advance 
of  the  piston  would  be  shut  and  the  one  behind  it  open  at  the 
same  time. 

The  lap  on  the  steam  side  should  always  be  greater  than  that 
on  the  exhaust  side,  and  the  difference  greater  the  higher  the 
velocity  of  the  piston. 

In  fast-running  engines,  alike  to  locomotives,  it  is  necessary  to 
open  the  exhaust  valve  before  the  end  of  the  stroke  of  the  piston, 
in  order  to  give  more  time  for  the  escape  of  the  steam. 


To  ascertain  the  Breadth  of  the  Ports. 

Half  the  throw  of  the  valve  should  be  at  least  equal  to  the  lap 
on  the  steam  side,  added  to  the  breadth  of  the  port.  If  this 
breadth  does  not  give  the  required  area  of  j^ort,  the  throw  of  the 
valve  must  be  increased  until  the  required  area  is  attained. 


To  compute  the  Stroke  of  a  Slide  Valve. 

KuLE. — To  twice  the  lap  add  twice  the  width  of  a  steam  port  in 
inches,  and  the  sum  will  give  the  stroke  required. 

Expansion  by  lap,  with  a  slide  valve  operated  by  an  eccentric 
alone,  cannot  be  extended  beyond  ^  of  the  stroke  of  a  piston 
without  interfering  with  the  efficient  operation  of  the  valve;  with 
a  link  motion,  however,  this  distortion  of  the  valve  is  somewhat 
compensated.  When  the  lap  is  increased,  the  throw  of  the  eccen- 
tric should  also  be  increased. 

"\^^len  low  expansion  is  required,  a  cut-off  valve  should  be  re- 
sorted to  in  addition  to  the  mam  valve. 


196  STEAM   AND   THl-]   STEAM-ENGINE. 

POWER  OF  STEAM. 

Mr.  Tredgokl  gives  the  following  table,  which  will  show  how 
the  power  of  the  steam  as  it  issues  from  the  boiler  is  distributed. 

In  a  Non-Condensing  Engine. 

Let  the  jiressure  on  the  boiler  be 10.000 

Force  required  to  produce  motion  of  the  steam  in  the 

cylinder  will  be 0.069 

Loss  by  cooling  in  the  cylinder  and  pipes 0.160 

Loss  by  frictiiin  of  the  piston  and  waste 2.000 

Force  required  to  expel  the  steam  into  the  atmosphere.  0.069 
Force  expended  in  opening  the  valves,  and  friction  of 

the  various  parts 0.622 

Loss  by  the  steam  being  cut  off  before  the  end  of  the 

stroke 1.000 

Amount  of  deductions  3.920 

Effective  pressure  6.080 

In  a  Condensing  Engine. 

Let  the  pressure  on  the  boiler  be ^10.000 

Force  required  to  produce  motion  of  the  steam  in  the 

cylinder 0.070 

Loss  by  cooling  in  the  cylinder  and  pipes 0.160 

Loss  by  friction  of  the  jtiston  and  waste 1.250 

Force  required  to  expel  steam  through  the  passages.  .0.070 
Force  rec^uired  to  open  and  close  the  valves,  raise  the 

injection  water,  and  overcome  the  friction  of  the 

axes 0.630 

Loss  by  the  steam  being  cut  oflf  before  the  end  of  the 

stroke 1.000 

Power  required  to  work  the  air  pump 0. 500 

Anion  lit  of  deductions  3.680 

Effective  pressure 6.320 

If  we  now  suppose  a  cylinder  whose  diametpr  is  24  inches,  the 
area  of  this  (;yliuder,  and  cousciiiiciitly  the  area  of  the  piston,  in 
square  inches  will  be 

24'JX.7854  =  452.39. 

Let  us  also  make  the  supjiosition  that  steam  is  admitted  into 
the  cylinder  of  such  power  as  exerts  an  effective  pressure  cm  the 
])ist()n  of  12  lbs.  to  the  s(piaro  inch;  therefore  4')2.3"J  X  12  = 
rA2H.(',H  lbs.,  tlnj  wholi!  I'ortie  with  wliicdi  the  piston  is  pressed. 
If  we  now  sui)i)os<i  tliat  tlie  li'nglli  of  the  stroke  is  five  feet,  and 
the  engine  makes  11  single  or  22  double  strokes  in  a  minute,  then 
the  jiiston  will  mov(!  through  a  sjiaee  of  22  X  5  X  2  =.  220  feet  in 
aiiiiniitr;  tlie  j)ower  of  tin;  engine  being  e<iuivah'nt  to  a  weight  ol 
5,428  lbs   raised  tlirougli  220  feet  in  a  minute. 

This  i-i  t'lo  most  certain  measure  of  the  pow(T  of  a  stoam-en- 
Kino.     It  is  usual,  however,  to  eatimato  the  effect  as  equivalent 


STEAM   AND    THE   STEAM-ENGINE.  197 

to  the  power  of  so  many  horses.  This  method,  however  simple 
and  natural  it  may  appear,  is  yet,  from  differences  of  opinion  as 
to  the  power  of  a  horse,  not  very  accurate;  and  its  employment 
in  calculation  can  only  be  accounted  for  on  the  ground,  that 
when  steam-engines  were  first  employed  to  drive  machinery,  they 
were  substituted  instead  of  horses;  and  it  became  thus  necessary 
to  estimate  what  size  of  a  steam-engine  would  give  a  power  equal 
to  so  many  horses. 

There  are  various  opinions  as  to  the  power  of  a  horse.  Accord- 
ing to  Smeaton,  a  horse  will  raise  2"2,91G  lbs.  one  foot  high  in  a 
minute.  Desaguliers  makes  the  number  27,500;  and  Watt  makes 
it  larger  still,  that  is,  33,000.  There  is  reason  to  believe  that 
even  this  number  is  too  small,  and  that  we  may  add  at  least  11,- 
000  to  it,  which  gives  44,000  lbs.  raised  one  foot  high  per  minute. 


BOILERS. 

Natural  Draught. 

Boilers  (Land)  should  be  set  at  an  inclination  of  .5  inch  in 
10  feet. 

Grates  (Coal). --They  should  have  a  superficial  area  of  1 
square  foot  for  every  15  lbs.  of  coal  required  to  be  consumed  per 
hour,  at  a  rapid  rate  of  combustion,  and  they  should  be  set  at  an 
inclination  toward  the  bridge  wall  of  1  inch  in  every  foot  of 
length.  When,  however,  the  rate  of  combustion  is  not  high,  in 
consequence  of  the  low  velocity  of  the  draught  of  the  furnace,  or 
the  fuel  being  insufiicient,  this  proportion  must  be  increased'  to 
1  square  foot  for  every  12  lbs.  of  fuel. 

With  wood  as  the  fuel,  their  area  should  be  1.25  to  1.4  that  for 
coal. 

The  width  of  the  bars  should  be  the  least  practicable,  and  the 
spaces  between  them  from  .5  to  .75  of  an  inch,  according  to  the 
fuel  used. 

Ash-pit, — The  transverse  area  of  it,  for  a  like  combustion  of 
15  lbs.  of  coal  per  hour,  should  be  .25  the  area  of  the  grate  sur- 
face for  bituminous  coal,  and  .33  for  anthracite. 

The  velocity  of  the  current  of  air  entering  an  ash-pit  may  be 
estimated  at  12  feet  per  second. 

Furnace  or  Chamber  (Coal). —The  \o\nme  of  it  should 
be  from  2.75  to  3  cubic  feet  for  every  square  foot  of  its  grate  sur- 
face.    (Wood.)     The  volume  should  be  4. G  to  5  cubic  feet. 

Combustion  is  the  most  complete  with  firings  or  charges  at  in- 
tervals of  from  15  to  2  J  minutes. 

The  volume  of  air  and  smoke  for  each  cubic  foot  of  water  con- 
verted into  steam  is  from  coal  1,780  to  1,950  cubic  feet,  and  for 
wood  3,900. 

Bridge  Wall  (Fine  boilers).— The  cross-section  of  the 
flues  or  tubes  should  have  an  area  of  1.7  to  2  square  inches  for 
each  lb.  of  coal  consumed  per  hour,  or  from  22.5  to  26  square 
inches  for  each  sqiiare  foot  of  grate,  for  a  combustion  of  13  lbs. 
of  coal  per  hour  ;  the  difference  in  the  area  depending  upon  the 


198  STEAM   AND   THE   STEAM-ENGINE.  | 

character  of  the  conformation  of  the  section  of  and  the  length  of 
the  passage  of  the  gases  ;  the  area  being  inversely  -with  the  dir 
ameter,  and  directly  as  the  length  of  the  flues,  tubes,  or  spaces 
between  them.  Thus,  in  horizontal  tubular  l)oilers,  the  area 
should  be  increased  to  27.5  and  31  square  inches;  in  vertical 
tubular,  to  32.5  and  3G  square  inches  ;  and  when  a  blast  is  used, 
the  area  may  be  decreased  to  15.5  and  20.5  square  inches. 

The  temperature  of  a  furnace  is  about  1000°,  and  the  volume 
of  air  required  for  the  combustion  of  1  lb.  of  bituminous  coal, 
together  with  the  products  of  combustion,  is  154.81  cubic  feet, 
which,  when  exposed  to  the  above  temperatiire,  makes  the  vol- 
ume of  heated  air  at  the  bridge  w.all  from  450  to  470  cubic  feet 
for  each  lb.  of  coal  consvimed  iipon  the  grates. 

Hence,  at  a  velocity  of  the  draught  of  about  36  feet  per  second, 
the  area  over  a  bridge  wall,  reqiiired  to  admit  of  this  volume  be- 
ing passed  off  in  an  hour,  would  be  .5  of  a  square  inch,  but  in 
practice  it  should  be  2  square  inches. 

When  13  lbs.  of  coal  per  hour  are  consumed  \ipon  a  sqiiarefoot 
of  grate,  13  X  2  =  2G  sqi;are  inches  are  required,  and  in  this  pro- 
portion for  other  quantities. 

The  temperature  of  the  heated  air  at  the  end  of  the  flues  should 
be  about  5l0^,  and  their  area  and  that  of  the  base  of  the  chimney 
should  be  .75  of  that  over  the  bridge  wall,  or  1.5  sqiiare  inches 
for  each  lb   of  coal  consumed  per  hour. 

When  the  area  of  the  flues  is  determined  upon,  and  the  area 
over  the  bridge!  wa'l  is  required,  it  should  be  taken  at  from  .7  to 
.8  the  area  of  the  lower  flues  for  a  natural  draught,  and  from  .5 
to  .  G  for  a  blast. 

Fines, — Their  area  should  decrease  with  their  length,  but 
not  in  proportion  with  the  reduction  of  tlie  temperature  of  the 
heated  air,  their  area  at  their  termination  biung  from  .7  to  .8  that 
of  their  calorimeter  or  area  immediately  at  the  bridge  wall. 

Large  flues  absorb  more  heat  than  small,  as  both  the  volume 
and  intensity  of  tlie  heat  is  great(^r  witli  equal  surfaces. 

The  temperature  of  the  ])aso  of  tlu^  cliimney,  or  the  termina- 
tion of  the  flues  or  tubes,  is  estimated  at  500';  and  the  base  of 
the  chimney,  or  the  calorimeter,  should  have  an  area  of  1.33 
square  inches  for  every  pound  of  coal  consumed  per  hour.  With 
tubes  of  small  dianu'ter,  compared  to  their  length,  this  propor- 
tion may  be  reduci'd  to  1  inch. 

The  admission  of  air  behind  a  bridge  wall  increases  the  tem- 
jjcratun!  of  tlie  gases,  but  it  must  bo  at  a  jwint  where  their  tem- 
j)eratnr<!  is  not  below  800'. 

I£ra/n>tuitioii.  1  scpiare  foot  of  grate*  surface,  at  a  combus- 
tion of  i;5  lbs.  coal  i)er  hour,  will  evaporate  2  cubic  feet  of  salt 
water  j)er  hour. 

A  sepians  foot  of  heating  surface,  at  the  above  combustion  of 
fuel,  will  evai>orate  from  4.33  to  5.33  lbs.  of  salt  water  per  Imur; 
and  at  a  (loiiibustinn  of  40  lbs.  coul  ]ier  liour  (as  u])on  the  West- 
ern rivers  of  the  U.  S. ),  from  10  <n  11  lbs.  fresh  water,  exclusive 
of  that  lost  by  blowing  out  froiu  the  boilers. 

12  to  15  square  feet  of  surface  will  evaporate  1  cubic  foot  of 


STEAM   AND   THE   STEAM-ENGINE.  199 

salt  water  per  hour  at  a  combustion  of  13  lbs.  coal  per  hour  per 
square  foot  of  grate. 

Note. —The  boilers  of  the  steamer  Arctic,  of  N.  Y.,  vertical 
tubular,  having  a  surface  of  33^  to  1  of  grate,  consuming  13  lbs. 
of  coal  per  square  foot  of  grate  per  hour,  evaporated  8.5G  lbs.  of 
salt  water  per  lb.  of  coal,  including  that  lost  by  blowing  out  of 
saturated  water. 

The  relative  evaporating  jjowers  of  iron,  brass,  and  copper  are 
as  1,  1.25,  and  1.5G. 

Water  Surface, — At  low  evaporations,  3  square  feet  are  re- 
qiiired  for  each  sqviare  foot  of  grate  surface,  and  at  high  evapora- 
tion 4  to  5  sqiiare  feet. 


Heating  Surfaces. 

Heating  Surfaces  (Sea-Water). — The  grate  an  d  heat- 
ing surfaces  should  be  increased  about .  07  over  that  for  fresh 
water. 

Relative  Value  of  Heating  Surfaces. 

Horizontal  surface  above  the  flame  =  1. 

Vertical   =     .5 

Horizontal  beneath  the  flame ^     .1 

Tubes  and  flues =     .56 

A  scale  one  sixteenth  of  an  inch  in  thickness  will  effect  a  loss 
of  14.7  per  cent,  of  fuel. 

One  square  foot  of  fire  surface  is  computed  to  be  as  effective  as 
three  of  heating  surface. 

When  the  combustion  in  a  furnace  is  complete,  the  tubes  may 
be  shorter  than  when  it  is  incomplete. 

Tubes  should  always  be  set  in  vertical  rows,  and  the  spaces 
between  them  should  be  increased  with  their  number. 


Boilers  with.  Internal  Furnaces. 

Fob  Coal,   13  lbs.  per  Hour  per  Square  Foot  of  Grate. 
(Natural  Draught.  ) 

Pressure  of  Steam  20  hs.  {Mercurial  Gauge),  and  20  Revolutions  of  the 

Engine  per  Minute. 

Fire  and  Flue  Surface."  {Arches  or  Flues  and  Return 
Flues.)— For  every  cubic  foot  of  steam  to  be  expended  in  the  steam 
cylinder,  for  a  single  stroke  of  the  piston  (computed  only  to  the 
point  of  cutting  off),  the  length  of  the  flues  and  steam  chimney 
not  exceeding  45  or  50  feet,  there  should  be  from  48  to  54  square 
feet. 

{Arches  or  Flues,  and  Tubes  or  Return  T\ibes.)  Horizontal  Return. 
— The  length  of  the  tiihea  and  steam  chimney  not  exceeding  30 
or  35  feet,  there  should  be  from  58  to  64  square  feet. 

*  Kstimated  from  above  the  grate  bars,  including  steam  chimney,  and  for 
sea- water. 


200  STEAM   AND    THE   STEAM-ENGINE. 

Vertical  Water  Tubes.— From  64  to  70  sqiiare  feet. 
Grates.— For  every  cubic  foot  of  steam  as  above,  there  should 
be  from  1.75  to  2.1  square  feet. 

Fob  CoAii,  30  lbs.  per  Hottb  per  Squabe  Foot  of  Grate. 
(Blast  ok  Exhaust.) 

Pressure  of  Steam  30  lbs.  (Mercurial  Gawje),  and  20  rievduikms  of  the 

Enrjine  per  Minnie. 

Fire  and  Fine  Surface.*  {Arclies  or  Flues  atul  Return 
Flues.)— Tot  every  cubic  foot  of  steam  to  be  expended  in  tha 
steam  cylinder,  for  a  single  stroke  of  the  piston  'computed  only 
to  the  point  of  cutting  off),  the  length  of  the  flues  and  steam 
chimney  not  exceeding  55  or  60  feet,  there  should  be  from  24  to 
28  square  feet. 

{Arches  or  Flues  ami  Tiibes.)  Ilorizonlal  Fuluni.— The  length  of 
the  tubes  and  steam  chimney  not  exceeding  30  or  35  feet,  there 
should  be  from  20  to  32  scjuare  feet. 

Vertical  Water  Tuhes.— From  32  to  35  square  feet. 

Grates. — For  every  cubic  foot  of  steam  as  above,  there  should 
be  from  1.15  to  1.35  square  feet. 


Boilers  with  External  Furnace  and  Internal  Flues. 
(Cylindrical  Flue.) 

Fob  Coal,  20  lbs.  per  Hour  per  Square  Foot  of  Gbate,  ob  fob 
Wood  at  40  lbs.     (Natural  Draught.  ) 

Pressure  oj  Steam  100  hs.  (Mercurial  Gauge),  and  20  devolutions  of 
the  Engine  per  Minute. 

Fire  ami  Flue  Surface.j -For  every  cubic  foot  of  steam 
to  be  expended  in  the  steam  cylinder  for  a  single  stroke  of  the 
piston  (computed  only  to  the  point  of  cuttingoff),  the  length  of 
the  flues  and  steam  chimney  not  exceeding  55  to  60  feet,  there 
should  be  from  100  to  108  square  feet. 

Grates.— For  every  cubic  foot  of  steam  as  above,  there  should 
be  from  3.8  to  4  srjuaro  feet. 

Western  Jioilers.— In  the  boilers  upon  the  Western  lakes 
and  rivers  of  the  United  States,  where  the  coal  consunuul  is  of 
the  very  best  quality,  and  the  smoke  pipes  are  carried  to  a  great 
heiglit,'the  combustion  of  coal  per  S(iuaro  foot  of  grate  per  hour 
rea<lily  reaches  40  lbs. 

1 J  cords  of  Western  wood  have  been  burned  per  hour  Tipon  48 
Bijuare  feet  of  grate. 

In  this  caK<!  tlie  units  above  given  may  be  reiluced  to  50  and 
54  for  heating  surface,  and  tlie  gratis  surface  decreased  to  1.K5 
un.l  2. 


*  EatlniBted  from  above  the  gnto  barn,  including  steam  chimney,  snd  for 
sea  watpr. 

t  KBtimated  from  bIkjto  tho  grato  bars,  including  steam  chimney,  where  one 
oxisU),  and  for  frcnb  water. 


STEAM   AND  THE   STEAM-ENGINE.  201 

Boilers  with  External  Furnace  and  Flue.    (Plain 

Cylindrical.) 

Fob  Coal,  20  lbs.  peb  Hour  pkr  Squaee  Foot  of  Gbate,  or  for 
Wood  at  40  lbs.     (Natural  Draught.  ) 

Pressure  of  Steam  100  Uis.  {Mercurial  Gauge),  and  20  Eevolidions  of 

the  Eivjine  per  Minute. 

Fire  and  Fine  Surface.*— For  every  cubic  foot  of  steam 
to  be  expended  in  the  steam  cylinder,  for  a  single  stroke  of  the 
piston  (computed  only  to 'the  point  of  cutting  off),  the  length 
of  the  flues  and  steam  chimney  not  exceeding  3U  feet,  there  should 
be  from  85  to  92  square  feet. 

Grates, — For  every  cubic  foot  of  steam  as  above,  there  should 
be  from  3. 8  to  4  square  feet. 

All  of  these  imits  are  based  upon  the  volume  of  furnace,  area 
of  bridge  wall,  or  cross-section  of  flues  or  tubes,  etc.,  as  given  in 
the  preceding  rules. 

The  ranges  given,  of  from  48  to  54,  24  to  48,  etc.,  are  for  the 
purpose  of  meeting  the  ordinary  differences  of  construction, 
thickness  of  metal,  etc. 

When  a  heater  is  used,  and  the  temperature  of  the  feed-water 
is  raised  above  that  obtained  in  a  condensing  engine,  the  pro- 
portions of  surfaces  may  be  correspondingly  reduced. 

Steam  JRooin. — There  should  be  from  2.5  to  3.5  times  the 
volume  of  steam  room  that  there  are  cubic  feet  of  steam  expended 
in  the  cylinder  for  each  single  stroke  of  the  piston  for  25  revolu- 
tions; or  the  volume  of  it  should  be  from  5  to  7  times  the  volume 
of  the  cylinder,  increasing  in  proportion  with  the  number  of 
revolutions. 

When  there  are  two  engines,  or  an  increased  number  of  revo- 
lutions, these  proportions  of  steam  room  must  be  increased. 

Felt  covering  to  a  boiler  and  steam  pipes  effects  a  very  material 
saving  in  fuel. 

Notes  — Four  copper  boilers,  with  a  natural  draught  and  bi- 
tuminous coal,  flues  40  feet  in  length,  including  steam  chimney, 
with  14  square  feet  of  fire  and  flue  surface,  and  .6  of  a  square 
foot  of  grate  surface  for  every  cubic  foot  in  the  cyliniers,  fur- 
nished steam  at  20  lbs.  pressure,  cut  off  at  J  of  the  stroke  of  the 
piston,  for  18.5  revolutions. 

The  mean  of  four  cases,  with  iron  boilers  and  anthracite  coal, 
with  a  blast,  flues  50  feet  in  length,  gave,  with  12.5  square  feet  of 
fire  and  flue  surface,  and  .5  of  a  square  foot  of  grate  surface  for 
every  cubic  foot  in  the  cylinders,  steam  at  35  lbs.  pressure,  cut 
off  at  ^  of  the  stroke  of  the  piston,  for  22  revolutions. 

The  space  in  the  steam  room  of  the  boilers  and  chimney  was 
about  5  times  that  of  the  cylinders  in  the  i^receding  cases. 


*  These  proportious  are  for  the  evaporation  of  fresh  water;  if  sea-water  is 
used,  the  surface  must  be  increased  .000. 

9* 


202  STEAM   AND   THE   STEAM-ENGINE. 

To  compute  the  Heating  and  Grate  Surface  required 
for  a  given  Evaporation,  or  Volume  of  Cylinder 
and  Revolutions. 

Operation. -lleduco  the  evaporation  to  the  required  volume 
of  cylinder,  number  of  revolutions  of  engine,  pressure  of  steam, 
r.nd  point  of  cutting  off;  then  reduce  these  results  to  the  range 
of  consumption  of  fuel  per  scjuare  foot  of  grate,  pressure  of  steam, 
and  number  of  revolutions  given  for  the  several  cases  at  pp.  199 
to  201,  and  multiply  them  by  the  units  given  for  the  surfaces 
required. 

Illustration.  —There  is  required  an  evaporation  of  492.24  cubic 
feet  of  salt  water  i)er  hour,  under  a  pressure  of  steam  of  17.3  lbs. 
per  square  inch,  stroke  of  engine  10  feet,  cutting  off  at  \  stroke, 
revolutions  15  per  minute,  and  c^onsumption  of  fuel  (coaf)  13  lbs. 
per  square  foot  of  grate  per  liour,  in  a  marine  boiler  having  in- 
ternal furnaces  and  viu-tical  tubes. 

Volume  of  steam  at  tliis  pressure  compared  with  water,  833. 

492.21  X  833 -i- 60  =  G833.93  cubic  feet  of  cylinder  per  minute. 

6833.93^  fsTx^  =  227.79  cubic  feet  of  cylinder  at  half  stroke. 

Then  ^^'^^ "^^  X  1 7. 3  ^  i()-jq^  cuI^j^.  feet  at  17.3  lbs.  pressure, 

and  l!!Z:^^i^i^  =  147.78,    which  X 'I'i,    the  unit  for  heating 
2J 
surface  for  a  vertical  tubular  boiler  at  20  lbs.  pressure  and  20 
revolutions,  =9753  48  square  feet. 

And  147.78  X2  =  the  unit  for  grate  under  like   condition  = 
295.5(5  square  feet. 

Note. The  steamer  Baltic  has  developed  all  the  elements  here 

given,  and  the  surface  of  her  boilers  and  grates  (for  one  engine) 
were  9,742  and  293.9  square  feet. 


To  compute  the  Consumption  of  Fuel  in  the  Fur- 
nace of  a  Boiler. 

The  Dimensions  of  the  Ci/lin/ler,  the  Pressure  of  the  S  earn,  the  Point  of 
Cultintj  Off,  the  Revofnlioni,  ami  the  Eixiporalion  of  the  JSoikrs  per 
Pound  of  Fad  per  Minute  beiwj  <fwcn. 

Rule. —Ascertain  the  volume  of  water  expended  in  steam,  and 
multiply  it  by  tlieweiglit  of  a  cubic  foot  of  the  water  us<'d;  dividu 
the  product 'by  the  evaporating  power  of  the  fuel  in  the  boiler 
undi-r  computation  in  i)ouuds  of  water,  and  add  thereto  the  loss 
per  cent,  by  blowing  off. 

Boiler  Plates  and  Bolts. 

Jioiler  riattH  oiul  Jioltn.  -The  .tmsilo  strcngtli  of 
vrrought  iron  plates  and  bolts  ranges  from  45,500  to    02,500  lbs. 


STEAM  AND   THE   STEAM-ENGINE.  203 

for  plates,  and  to  65,00  for  bolts,  being  increase-l  wlien  subjected 
to  a  moderate  temperature. 

The  mean  tensile  strength  of  copiDer  plates  and  bolts  is  33,000 
lbs.,  being  reduced  when  subjected  to  a  temperature  exceeding 
120°:  at  212°  being  32,000  lbs.,  and  at  555°  but  25,OO0  lbs. 


Bursting  and  Collapsing  Pressures. 

The  computation  for  plates  and  bolts  should  be  based,  so  far 
as  may  be  practicable,  xipon  their  exact  tensile  strength.  When- 
ever, then,  the  strength  of  plates  is  ascertained,  there  should  be 
deducted  therefrom  one-half  for  single  riveting  and  three-tenths 
for  double  riveting,  and  the  remainder  divided  by  a  factor  of 
safety  of  three.  When  the  exact  strength  cannot  be  ascertained, 
a  factor  of  six  should  be  used  both  for  plates  and  bolts. 

The  resistance  to  collapse  of  a  flue  or  ti;be  is  much  less  than 
the  resistance  to  bursting;  the  ratio  cannot  well  be  determined, 
as  the  resistance  of  a  llue  decreases  with  its  length,  ox  that  of 
its  courses. 

With  an  ordinary  cylindrical  boiler,  4  feet  in  diameter,  single 
riveted,  '20  feet  in  length,  with  flues  15^  inches  in  diameter, 
shell  5-16  thick,  flues  \  in.,  the  relative  strengths  are:  Bursting, 
350  lbs.;  Collapsing,  152  lbs. 


To  compute  the  Thickness,  Maximum  Working 
Pressure,  and  Diameter  of  a  Wrought  Iron  Boiler 
or  Flue. 

For  Service  in  Salt  Water.— Add  one-sixth  to  the  thick- 
ness of  the  plate  or  diameter  of  the  bolt. 

Thickness.  Kule. — Multiply  the  diameter  in  inches  by  half 
the  maximum  working  pressure  in  lbs.  per  sqiiare  inch,  and 
divide  the  product  by  9,000  (one-sixth  of  54,000)  for  single  rivet- 
ing, and  12,500  for  double,  and  the  result  will  give  the  thickness 
in  decimals  of  an  inch. 

Pressure.  Ruu:.— Multiply  the  thickness  by  9,000  or 
12,500,  as  before  given;  divide  the  product  by  the  diameter,  and 
twice  the  quotient  will  give  the  maximum  pressure  in  pounds. 

Diatnefer.  Kule  —Multiply  the  thickness  by  9,000  or 
12,500,  as  before;  divide  the  product  by  half  the  maximum  press- 
ure, and  the  quotient  will  give  the  diameter  in  inches. 

Example. — The  diameter  of  a  single  riveted  wrought-iron  boil- 
er is  42  inches,  and  the  plates  i  of  an  inch  in  thickness;  what  is 
its  maximum  working  pressure  ? 

l?i^^X2  =  1101bs.; 

and  what  its  thickness  at  this  pressure  ? 

42X110^ _  257  j^. 
9000 


204  STEAM   AND   THE   STEAM-ENGINE. 

To  compute  th.e  Diameter  of  Stay  Bolts. 

EuLE. — Multiply  the  distance  between  their  centres  in  inches 
by  the  square  root  of  the  quotient  of  the  maximum  working 
pressure,  divided  by  5,5U0  for  wrought  iron,  and  4, ICO  for  copper, 
and  the  result  will  give  the  diameter  of  the  body  of  the  bolt  in 
inches. 

Example. — The  maximum  working  pressure  of  a  wrought  iron 
boiler  is  110  lbs.,  and  the  distance  apart  of  the  bolts  is  6  inches; 
■what  should  be  their  diameter  ? 

6^     /il^^Gx  y. 02  =  6  X. 1414  =  .85  in. 
^  V  55U0 


To  compute  the  Distance  apart  of  Stay  Bolts. 

EuLE. — Multiply  the  square  root  of  the  quotient  of  5,500  for 
wrought  iron,  and  of  4,1()U  for  copper,  divided  by  the  maximum 
working  pressure,  by  the  diameter  of  the  bolt,  iind  the  product 
will  give  the  distance  in  inches. 

Example. — The  maximum  working  pressure  of  a  wrought  iron 
boiler  is  110  lbs.,  and  the  diameter  of  the  stay  bolts  is  .85  inch; 
what  should  be  their  distance  apart  ? 

'!^  X  .85  =  y  50  X  .85  =  6  ins. 
110 

Note. — "Where  stays  are  secured  by  keys,  their  ends  should  be 
1 J  times  the  diameter  of  the  stay,  the  dei)th  of  the  slot  l.G  of  the 
diameter  of  stay,  and  the  width  .3. 


V^ 


To  compute  the  Thickness  of  Flat  Surfaces  in  a 
Wrought  Iron  Boiler. 

Rule. — Multiply  the  maximum  working  pressure  by  the  square 
of  the  distance,  or"  the  area  of  the  surface,  between  the  centres  of 
the  stays  in  inches  ;  divide  the  product  by  15,500,  and  the 
quotient  will  give  the  thickness  in  inches. 

Ex.YMPLE.— Take  the  elements  of  the  preceding  case. 

li^L>L^  =  .255  in. 

StaiJ  Bolts.  Iron  stay  bolts,  \  ins.  in  diameter,  screwed 
into  a  copixr  plate  g  thick,  drew  at  a  strain  of  18,2f'.()  ll>s. 

A  liki-  stay  bolt,  sc.n^wed  and  riv<'ted  into  an  iron  plate,  drew 
at  a  strain  of  28, TOO  lbs. 

A  like  stay  bolt  of  copper,  screwed  and  riveted  into  a  cojjpor 
plate,  drew  at  a  strain  of  10,205  lbs. 

Hence,  stay  boitn  when  scrowod  and  riveted  are  J  stronger 
than  when  screwed  aU)Ue. 


MEASURES    AND   WEIGHTS. 


205 


METRIC  SYSTEM  OP  MEASURE  J 
WEIGHTS. 

ACCOEDING   TO   AcT    OF    1866. 


AND 


Equivalents  of  Old  and  New  IT.  S.  Measures. 
Length.  Surface. 


Inch 
Foot 
Yard 


1  Chain 


Furlong 
Mile 


Metres. 
.02540005 
.3048006 
.9144018 
20.1168396 
201.168396 
1609.347168 


Volume. 


1  Fluid  Dram 
1  Fluid  Ounce 
1  Fluid  Pound 
1  Gill 

1  Wine  Pint 
1  Dry  Quart 
1  Wine  Quart 
1  Wine  Gallon 


Litres.* 

:  .f036967 
:  .0295739 
:  .35488656 
:  .1182955 
:  .4731821 
1.1012344 
:  .9463642 
:  3. 7854579 


Square  Metres. 

1  Inch  =  .000645161 

1  Foot  =  .092903184 

1  Yard  =  .836128656 

1  Eod  =       25.292891844 

1  Rood  =  1011.71507376 

1  Acre  ^  4046.86269501 

Weight. 

Grammes. 
1  Grain  =     .0648004 

1  Scruple  ==   1.296008 

1  Pennyweight  =   1.5552096 
1  Dram  =   3.888024 

1  Ounce  (Troy)  =31.104192 
1  Ounce  t  =28.350175 

1  Pound  =453.6028 

1  Ton        =1016070.272 


Note. — A  square  metre  is  1549.99G9  square  inches,  but  by  Act 
of  Congress  it  is  declared  to  be  1550  square  inches;  hence  the 
litre  (cubic  decimetre)  =61.023377953  cubic  inches.  In  the  Act 
of  Congress,  a  litre  is  declared  to  be  61.022  cubic  inches,  which 
is  erroneous,  as  here  shown,  by  the  .001  -)-  of  an  inch. 


Measures  of  Length. 


Denominations  and  Values. 

Equivalents  in  use. 

Mj'riametre. 
Kilometre.  . . 
Hectometre 
Decametre. . 

Metre     

Decimetre  . . 

10,000  metres. 

1.000 

100 

10 

1 

-j^ofa 

6.2137  miles. 
.62137    "  or  3280  ft.  &  10  ins. 
328  ft.  and  1  inch. 
393.7  inches. 
39.37      " 
3.937      " 

Centimetre. . 
Millimetre. . 

100 

1           <(             >( 

TOGO 

.3937     " 
.0394     " 

*  G1.023  cubic  inches. 


t  AvoirdupoiB. 


206 


MEASURES  AND   WEIGHTS. 
Measures  of  Surface, 


Denomiuatious  and  Values. 

Equivalents  in  use. 

Hectare 

Are 

Centare 

10,000  sq.  metres. 

100  " 

1    ((           (( 

2.471  acres. 

119.6  square  yards. 

1550  square  inches. 

Measures  of  Volume. 


Denominations  and  Values. 

Equivalents 

iu  u  e. 

Names. 

No.  of 
Litres. 

1,000 

100 
10 

1 
iV 

.  1- 

1  00 
Tooo 

Cubic  Measure. 

Dry  Measure. 

Liq.  or  Wine 
Measure. 

Kilolitre  J 
orStere  j 
Hectolitre 
Decalitre  . . 

Litre 

Decilitre  . . 
Centilitre  . . 
Millilitre. . . 

1  cubic  metre 

10                              . 

10     "     decimetres 
1     " 

10     "     centimetres 
1     " 

1.308  cub.  yds. 

2bh.,  3.35  pks. 

9.08  quarts. 
.908     " 

=5.1022  cub.  ins. 
.6102     "     " 
.061       "     " 

264. 17  gals 

26.417    " 
2.6417    " 
1.0567  qts. 
.845  gill. 
.338  fld.  oz 
.27    "drm 

Weights. 


Denominations  and  Values. 

Equiv.  in  use. 

,            Names. 

Number  of 
Grammes. 

Weight  of  Volume  of  Watt>r 
at  its  Maximum  Density. 

AvoirdupolB 
Weight. 

Millii^r  or  Tonneau 
Quintal 

1.000.000 

lOO.OO  ) 

10.000 

1,000 

100 

10 

1 

I 

10 

.So 

logoff 

1  cubic  metro. 

1  hectolitre. 

10  litres. 

1 

1  decilitre. 

10  cubic  centimetres. 

1 

1.1 

Iff 

10  cubic  millimetros. 

1          (i                (1 

2204.6  Ib.s. 
220.46     '• 

Myriagramme   .... 
Kilogram,  or  Kilo. 

Hectogramme. 

Dc'cagramme  

Gramme 

22.046     " 
2.2046     " 
3.5274  oz. 
.3527    " 
15.432  gra. 

Decigramme 

Centigramme 

Mllligramnjc 

1.5432     •' 
.1543     " 
.0154     " 

For  measuring  Rurfaces,  the  scjuaro  Docami'tre  is  used  under 
the  tiriii  of  Arr;  the  Hi'ctar«s  or  100  Arcs,  is  ciiual  to  about  2 
acres. 

The  Unit  of  Capacity  is  the  cubic.  Decimetre  or  Ijilre,  and  tho 
HcrieH  of  nieiiHurcH  is  formed  in  the  same  way  as  iu  tho  case  of  the 
tabic  of  lengths. 


ALLOYS   AND    COMPOSITIONS. 


207 


The  cubic  Metre  is  the  unit  of  measure  for  solid  bodies,  and  is 
wrmed  Stere. 

The  Unit  of  Weight  is  the  Gramme,  which  is  the  weight  of  one 
cubic  centimetre  of  pure  water  weighed  in  a  vacuum  of  4"^  Centi- 
grade, or  39  \  2  Fahrenheit,  which  is  about  its  temperature  of 
maximum  density. 

In  practice,  the  terra  cubic  Centimetre,  abbreviated  C.  C,  is 
used  instead  of  Millilitre,  and  cubic  Metre  instead  of  Kilolitre. 


ALLOYS  AND   COMPOSITIONS. 
Compositiou  for  Welding  Cast  Steel. 

Borax,  10  parts;  sal-ammoniac,  1  part.  Grind  or  pound  them 
IroTighly  together;  fuse  them  in  a  metal  pot  over  a  clear  tire,  con- 
tinuing the  heat  until  all  spume  has  disappeared  from  the  sur- 
face. When  the  liquid  is  clear,  pour  the  composition  out  to  cool 
and  concrete,  and  grind  to  a  fine  j^owder;  then  it  is  ready  for  use. 

To  use  this  composition,  the  steel  to  be  welded  should  be 
raised  to  a  bright  yellow  heat;  then  dip  it  in  the  welding  powder, 
and  again  raise  it  to  a  like  heat  as  before;  it  is  then  ready  to  be 
submitted  to  the  hammer. 


Fusibla  Compounds 

Compounds. 

Zinc. 
33.3 

Tin. 

25 

19 
12 

Lead. 

25 
33.:^ 
31 
25 

Bism'h. 

Cadm. 

Rose's,  fusing  at  200' 

50 
33.4 

50 
50 

Fusing  at  less  than  200°      

Newton's,  fusing  at  less  than  212" 
Fusing  at  150°  to  160° 

13 

Soldering  Fluid  for  Use  with  soft  Solder. 

To  2  llui  1  oz.  of  nuiriatic  acid  add  small  jiieces  of  zinc  until 
bubbles  cease  to  rise.  Add  half  a  teaspoonful  of  sal-ammoniac 
and  2  fluid  oz.  of  water. 

By  the  application  of  this  to  iron  or  steel,  they  may  be  soldered 
without  their  surfaces  being  previously  tinned. 


Babbitt's  Anti-Attrition  Metal. 

Melt  4  lbs.  copper  ;  add,  by  degrees,  12  lbs.  best  Banca  tin,  8 
lbs.  regulus  of  antimony,  and  12  lbs.  more  of  tin.  After  4  or  5 
lbs.  tin  have  been  ad  lerl,  reduce  the  heat  to  a  dull  red,  then  add 
tiie  remainder  of  the  metal  as  above. 

This  composition  is  termed  hardening;  for  lining,  take  1  lb.  of 
this  hardening,  melt  with  it  2  lbs.  Banca  tin,  which  produces  the 
lining  metal  for  use.  Hence,  the  proportions  for  lining  metal 
ar'j  i  lbs.  of  copper,  8  of  regulus  of  antimony,  and  9  J  of  tin. 


208  TEMPERING. 

TEMPERING. 

Tlio  article  after  being  completed  is  liurdenecl  by  bein;^  heated 
gradually  to  a  bright  red,  and  then  phinged  into  cold  water;  it  ia 
then  tempered  by  being  warmed  gradually  and  equably,  either 
over  a  fire,  or  on  a  piece  of  heated  metal  till  of  the  color  corre- 
sponding to  the  purpose  for  which  it  is  required,  as  per  table 
below,  when  it  is  again  plunged  into  water. 

Corresponding  Temperature. 

A  very  pale  straw 430'     Lancets  | 

Straw" 450'     llazors    \ 

Darker  straw 470°     Penknives  |  All  kinds  of  wood  tools. 

Yellow 490°     Scissors      {      Screw  taps. 

Brown  yellow 500'' )  Hatchets,  Chipping  Chisels, 

Slightly  tinged  purple. 520'  V      Saws 

Purple 530°  )  All  kinds  of  percussive  tools. 

Dark  purple 550°  )  o„_;„„„ 

Blue    ...    57(^o  f  feprmgs. 

Dark  blue 600°    Soft  for  saws. 


To  Temper  by  the  Thermometer. 

Put  the  articles  to  be  tempered  into  a  vessel  containing  a  suffi- 
cient quantity  to  cover  them  of  oil  or  tallow;  sand;  or  a  mixture 
of  8  parts  bismuth,  5  of  lead,  and  3  of  tin,  the  whole  to  be 
brought  up  to,  and  kept  up  at  the  heat  corresponding  to  the 
hardness  required,  by  means  of  a  suitable  thermometer,  till  heated 
ciinally  throughout;  the  articles  are  then  withdrawn  and  plunged 
into  cold  watir.  If  no  thermometer  is  available,  it  may  be  ob- 
served that  oil  or  tallow  begins  to  smoke  at  430 '  or  straw  color, 
and  that  it  takes  fire  on  a  light  being  presented,  and  goes  out 
when  the  light  is  withdrawn,  at  570°  or  blue. 


Case   Hardening. 

Put  the  articles  requiring  to  be  hardened,  after  being  finished 
but  not  j)olished,  into  an  iron  box  in  layers  with  animal  carbon, 
that  is,  horns,  hoofs,  skins,  or  leath(;r,  partly  burned  so  as  to 
be  capable  of  being  reduced  to  jjowder,  taking  can;  tliat  every 
part  of  the  iron  is  completely  surrounded;  make  tlie  box  tight 
with  a  lute  of  sand  and  clay  "in  equal  parts,  put  the  whole  into 
the  fire,  and  keep  it  at  a  light  red  lieat  for  half  an  hour  to  two 
liours,  aceordiiig  to  the  di])th  of  hardiiieil  surface  retpiin^d,  then 
empty  tlie  contents  of  the;  box  into  water,  care  being  taken  tliat 
any  articles  liable  to  buckle  bo  put  in  separately  and  carefully, 
end  in  first. 

Cast  iron  nny  be  case  hardened  as  follows  : 

Hring  to  a  red  heat,  and  roll  it  in  a  mixture  of  powdered  prns- 
siate  of  potiisli.  H'dtix'trr',  and  sul-ammoniac  in  equal  i)arts,  tlien 
l>buigc  it  into  11  balli  containing  2  o/,.  pru.ssiatu  of  potash,  an  I  i 
oz.  Halanimoniao  p-ir  gallmi  of  water. 


WEIGHT   OF    CASTINGS. 


209 


To  find  the  Weight  of  any  Casting. 

Width  in  J-  in.  X  thickness  in  I  in.,  or,  vice  versa,  -f-  10  X 
length,  ft.  =  wt.  lbs. ,  cast  iron. 

For  instance  :  To  find  the  weight  of  a  casting  3}  in.  X  H  in.  X 
2  ft.  6  in.  long. 

13  X  9-i- 10  =  11.7  X  2.5  =  29.25  Ib.s. 

This  rule  is  very  useful,  and  can  easilj'  be  remembered  in  the 
following  form  : 

Width  in  ]  in.  X  thickness  in  J  in. ;  or,  vice  versa,  cut  off  1 
figure  for  decimal,  the  resiilt  is  lbs.  per  foot  of  length. 

For  wrought  iron  add  1-20  to  the  result ;  for  lead  add  ^  ;  for 
brass  add  1-7  ;  for  copper  add  1-5. 

To  FIND  THE  Weight  from  the  Aeeas. 

Area,  sq.  ins.  X  length,  ft.  X  3  1-7  =  wt.  lbs.  cast  iron. 

Multiplier  for  cast  iron   3.  IfiG,  or  3  1-7 

"  "    wrought  iron 3.312,   "3^ 

"  "   leiid     4.854 

"  "    brass      3.644 

"  "    copper :i87 

or,  area  sq.  ins.  X  10  =  lbs.  per  yard  for  wrought  iron. 

To   FIND    the   W"eIGHT   IN    CwTS. 

Area,  sq.  ins  X  length,  ft. -^31.9  =  wt.  cwts.  cast  iron. 
For  wrought  iron  -^  33.6. 

To   compute   the  Weight   or  Cast  ^Ietal   by  the  Weight  of 
THE  Pattern,  avhen  the  Pattern  is  of  White  Pine. 

Rttle. — Multiply  the  weight  of  the  pattern  in  lbs.  by  the  fol- 
lowing multiplier,  and  the  product  will  give  the  weight  of  the 
casting.     Iron,  14 ;  brass,  15  ;  lead,  22  ;  tin,  14  ,  zinc,  13.5. 


Table  of  Alloys. 


AUojb  hi^^■ing  a  density  ffrentor  than  the 
Meiin  of  their  Conaliluents. 


Gold  and  zinc. 
Gold  and  tin. 
Gold  and  bismuth. 
Gokland  antimony 
Go'd  and  cobalt. 
Silver  and  zinc. 
Silver  and  lead. 
Silver  and  tin. 
Silver  and  bismuth 


Silver  &  antimony. 
Copper  and  zinc. 
Copper  and  tin. 
Cojiper  &paUadium 
Copper  &  bismuth. 
Lead  and  antimony 
Platinum  &  molyb- 
denum, (ninth. 
Palladium  and  bis- 


Alloys  having  a  density  legs  than  the 
Mean  ot  their  Constituents. 


Gold  and  silver. 
'Told  and  iron. 
Gold  and  lead. 
Gold  and  copper. 
Gold  and  iridium. 
Gold  and  nickel. 
Silver  and  copper. 
Silver  and  lead. 


Iron  and  bismuth. 
Iron  and  antimony 
Iron  and  lead 
Tin  and  lead. 
Tin  and  palladium. 
Tin  and  antimony. 
Nickel  and  arsenic. 
Zinc  and  antimony 


210 


PRACTICAL   MECHANICAL   RECEIPTS. 


Alloys  of  Copper  and  Zinc,  and  Copper  and  Tin. 

Composition  by 
Weight  per  cent 

'S  > 
8667 

Color. 

s"Hs 

—    X     X  » 

Characteristic  Tropertiea,  &c. 

Copper 

rile  red. 

24.6 

Malleable. 

100.00      Zinc 

6895 

Bluish  gray. 

15.2 

Brittle. 

8-i.0-2- 

-lfi.98 

8415 

Yellowish  red. 

13.7 

Bath  metal. 

7!).65- 

-iO.35 

8448 

((           i( 

14.7 

Dutch  brass. 

74.58- 

-25.42 

8397 

Palo  yellow. 

13  1 

Rolled  sheet  brass. 

6rt.l8- 

-33.82 

8299 

Full  yellow. 

12.5 

British  brass. 

4'J.i7- 

-50.53 

8230 

<l               .4 

9.2 

Germaii  brass. 

32.85- 

U67.15 

8283 

Deep  yellow. 

19. 'J 

Watchmakers'  brass. 

3i).30- 

L69.70 

783(1 

Silver  white. 

2.2 

Very  brittle. 

24.50- 

-75.50 

744' 1 

\sli  trrav. 

3.1 

Brittle. 

19.65- 

-80.35 

7371 

(>     11  " 

1.9 

White  button  metal 

Tin 

7291 

White. 

2.7 

84.29-1 

f-15.71 

8561 

Ilcddish  yellow 

16.1 

Gun-metal. 

81.10- 

-18.9i) 

S459 

I'ellowish  red. 

17.7 

Gun-metal  and  bronze. 

78.1)7- 

-21.03 

8728 

i(        (( 

13.6 

Hard,  mill  brasses. 

34.92- 

-65.08 

8065 

White. 

1.4 

Small  bells. 

15.17- 

-Hi.ys 

7417 

Very  white. 

3.1 

Speculum  metal. 
Files,  tough. 

1L82- 

-88.13 

7472 

(i        (t 

3.1 

Note.  — No  simple  binary  alloy  of  copper  and  zinc,  or  of  copper 
and  tin,  works  iis  pleasantly  in  turning,  planing,  or  filing,  as  if 
combined  with  a  small  proportion  of  a  third  fusible  metal;  gen- 
erally lead  is  added  to  copper  and  zinc,  and  zinc  to  copper  and 
tin. 

Alloys  for  Bronze. 

Professor  Hoffman,  of  the  Prussian  artillery,  lias  made  experi- 
ments with  the  view  of  obtaining  a  good  statuary  bronze,  and 
recommends  the  alloys  ranging  between  the  two  following  ad- 
mixtures : 

1st.  To  produce!  the  reddest  l)ronze. 

88.75  copper  zinc  (7  atoms  copper,  1  atom  zinc). 
11.25  copper  tin  (3  atoms  copper,  1  atom  tin). 


100.00 


2d. 


To  produce  a  cheap  bronze,  with  a  bright  yellow  color,  al- 
most golden. 
93.5  copper  zinc  (2  atoms  copper,  1  atom  zinc). 
6.5  copper  tin  (3  atoms  copper,  1  atom  tin). 


100.00 


GllU'-  Powdered  chalk  ailded  to  common  glue  strengthens  it 
A  g''ie  which  will  resist  the  action  of  water  is  made  by  boiling  1 
pound  of  glue  in  2  (j>iarts  of  skimmed  milk 


PRACTICAL    MECHANICAL    RECEIPTS.  211 

To  Joint  LiCftd  Pipes.  —Widen  out  the  end  of  one  pipe 

with  a  taper  wood  drift,  and  scrape  it  clean  inside ;  scrape  tho 
end  of  the  other  pipe  outside  a  little  tapered,  and  insert  it  in  tho 
former;  then  solder  it  with  common  lead  solder  as  before  de- 
scribed; or  if  required  to  be  strong,  rub  a  little  tallow  over,  and 
cover  the  joint  with  a  ball  of  melted  lead,  holding  a  cloth  (2  or  3 
plies  of  greased  bed-tick)  on  the  under  side;  and  smoothing  over 
with  it  and  the  plumber's  iron. 

To  2>oUsh  Brass. — When  the  brass  is  made  smooth  by- 
turning  or  filing  with  a  very  fine  file,  it  may  be  rubbed  with  a 
smooth  fine  grained  stone,  or  with  charcoal  and  water.  When  it 
is  made  quite  smooth  and  free  froui  scratches,  it  may  be  polished 
with  rotten  stone  and  oil,  alcohol,  or  spirits  of  turpentine. 

To  clean  Bi'ftss. — If  there  is  any  oily  substance  on  the 
brass,  boil  it  in  a  solution  of  potash  or  strong  lye.  Mix  equal 
quantities  of  nitric  and  sulphuric  acids  in  a  stone  or  earthen 
vessel,  let  it  stand  a  few  hours,  stirring  it  occasionally  with  a 
stick,  then  dip  the  brass  in  the  solution,  but  take  it  out  imme- 
diately and  rinse  it  in  soft  water,  and  wipe  it  in  sawdust  till  it  is 
dry. 

To  fill  Soles  ht  Castings. — Lead,  9  i^arts;  antimony,  2; 
and  bismuth,  1:  to  be  melted  and  poured  in. 

Babbitt  ilffef'fZ— Copper,  4  lbs.;  regulus  of  antimony,  8 
lbs. ;  Banca  tin,  88  lbs. 

To  soften  Iron  or  Steel.~\noint  it  all  over  with  tallow; 
heat  it  in  a  charcoal  fire;  then  let  it  cool. 

To  restore  Burnt  Steel.— Bovax,  3  oz. ;  sal-ammoniac,  8 
oz. ;  prussiate  of  potash,  3  oz. ;  blue  clay,  2  oz. ;  resin,  LV  lbs.; 
water,  1  gill;  alcohol,  1  gill.  Put  all  on  a  fire,  and  simmer  until 
it  dries  to  a  powder;  then  heat  the  steel  and  dip  it  into  this  pow- 
der and  hammer  it. 

Babbitt  JMetal. — Block  tin,  8  lbs. ;  antimony,  2  lbs. ;  copper, 
1 J  lbs.     If  the  metal  is  too  hard  add  a  little  lead. 

Composition  to  toughen  Steel. — Resin,  2Jlbs. ;  tallow, 
2|  lbs.;  i^itch,  IJ  lbs.  Melt  together,  and  apjjly  the  steel  while 
hot. 

Substitute  for  Borax. — Copperas,  2  oz. ;  common  salt,  5 
oz. ;  saltpetre,  1  oz. ;  black  oxide  of  manganese,  1  oz. ;  prussiate 
of  potash,  li  oz.  Pulverize  and  mix  with  3},  lbs.  of  welding  sand: 
use  same  as  borax. 

Tempering  Liquids. — Salt,  4  oz. ;  saltpetre,  ^  oz. ;  pul- 
verized alum,  1  oz. ;  soft  water,  1  gallon.  Heat  to  a  cherry  red, 
but  do  not  draw  the  temper. 

JLnother. — Saltpetre  and  alum,  each  2  oz. ;  sal-ammoniac,  ^  oz. ; 
salt,  li  lbs.;  soft  water,  two  gallons.  Heat  to  a  cherry  red  and 
plunge  in. 


212  PRACTICAL   MECHANICAL   RECEIPTS. 

Case- Hardening  for  Iron. — Heat  the  iron  to  a  bright 
cherry  red,  then  roll  it  in  a  composition  composed  of  equal  parts 
of  sal-ammoniac,  saltpetre,  and  prussiato  of  jjotash;  cover  the 
iron  thoroughly  with  this  composition,  and  plunge  it  while  hot 
into  a  bath  composed  of  2.\  oz.  prussiate  of  potash,  i^  oz.  sal- 
ammoniac,  and  1  gallon  of  Avater. 

To  restore  Surnf  Steel. — Borax,  3  lbs.;  sal-ammoniac,  1 
lb. ;  prussiate  potash,  ^  lb. ;  resin,  i  lb. ;  alcohol,  1  gill;  soft  water, 
1  pint.  Put  into  an  iron  pan  ami  hold  over  a  slow  fire  until  it 
comes  to  a  slow  boil  and  until  the  liquid  matter  evajiorates;  be 
careful  to  stir  it  well  from  the  bottom  and  let  it  boil  slow.  This 
receipt  is  very  valuable,  no  matter  how  bad  the  steel  is  burned, 
it  will  restore  and  make  it  as  durable  as  ever. 

To  hlne  Gun  Sarrels.—AYiply  nitric  acid  and  let  it  eat 

into  the  iron  a  little  ;  then  the  latter  will  be  covered  with  a  thin 
film  of  oxide.     Clean  the  barrel,  oil,  and  burnish. 

Lininff  So.ves  with  Babbitt  Metal. — Heat  the  box  hot 
enough  to  melt  the  metal;  then  smoke  the  shaft  where  the  metal 
is  to  be  poured  in;  this  insures  its  coming  out  of  the  box  readily 
after  it  is  cold.  After  smoking  the  shaft  put  it  into  the  box  and 
l>ut  putty  around  the  ends,  taking  care  not  to  press  too  hard, 
or  the  putty  will  be  forced  into  the  box;  then  heat  your  metal 
and  pour  in,  letting  it  stand  until  cold;  then  drive  out  the  shaft 
and  it  is  complete. 

To  estimate  the  Percentatje  of  Iron  in  Ores.—Fre- 

parc  a  crucible  of  refractory  clay  by  pressing  into  it  successive 
layers  of  moistened  powdered  charcoal  until  full  and  solid;  clear 
out  a  cavity  by  removing  the  central  portion.  Take  200  grains  of 
the  powdered  ore,  and  mix  it  with  the  same  weight  of  dry  slacked 
lime,  and  50  grains  charcoal ;  if  necessary  a  little  carbonate  of 
soda  may  be  used  with  very  refra(^tf)ry  ores  ;  introduce  this  mix- 
ture into  the  crucible  and  lute  it  up.  Expose  the  crucible  to  a 
moderate  heat  until  the  contents  of  the  crucible  are  dry,  then 
apply  and  maintain  for  half  an  hour  the  full  heat  of  a  blast  fur-  ■ 
nace.  Then  remove  the  crucible,  tap  it  steadily  on  the  edge  of 
the  fiiniaee,  so  as  to  bring  the  metallic  portion  of  its  contents 
together  at  the  bottom  ;  and,  when  cool,  break  the  crucible  open. 
The  iron  will  be  found  in  a  ch^an  button  at  the  bottom  of  tho 
slag.  Clean  tlie  iron  with  a  scratch  brush,  and  weigh  it.  Its 
weight,  divided  by  2,  will  give  the  percentage  of  richness  of  tho 
ore  untb'r  cxuininatinn. 

Todititin<inisU  Wromjltt  and  Cast  Iron  f nun  Steel. 

— Eisner  prfxluces  a  briglit  surface  by  polishing  or  filing,  and 
applies  a  drop  of  nitric  acid,  whicli  is  allowed  to  remain  there 
for  one  or  two  minutes,  and  is  then  waslied  off  with  water.  Tho 
spot  will  then  look  a  pale  lusliygray  on  wrought  iron,  a  brownish 
black  r)u  steel,  a  d'cp  bhu^k  on  i^ast  iron.  It  is  tlie  carbon  pres- 
ent in  various  proiiortions  which  i)roduce8  the  differenoe  in  aj)- 
pearaucc.  ' 


PEACTICAL  MECHANICAL   EECEIPTS.  213 

Vev}/  deep  Casc-IIa rdeni ngfor  Iron.  —Put  the  iron  into 
a  crucible  with  cj'anide  of  potash.  Cover  over  and  heat  together, 
then  plunge  into  water.  This  process  will  harden  to  the  depth 
of  three  inches. 

To  hit  part  to  Cast  Iron  the  Appearance  of  Bronze. 

— The  article  to  be  so  tr  ■ated  is  first  cleaned  with  gi-eat  care,  and 
then  coated  with  a  uuiforju  film  of  some  vegetable  oil;  this  done, 
it  is  exposed  in  a  furnace  to  the  action  of  a  high  temperature, 
which,  however,  must  not  be  strong  enough  to  carbonize  the  oil. 
In  this  way  the  cast  iron  a'  sorbs  oxygen  at  tlic  moment  the  oil 
is  decomposed,  and  there  is  formed  at  the  surface  a  thin  coat  of 
brown  oxide,  Avhicli  adheres  very  strongly  to  the  metal,  and  will 
admit  of  a  high  polish,  giving  it  qiaite  the  appearance  of  the 
finest  bronze. 

Brown  Tint  for  Iron  and  Steel. —Biaaolve  in  4  parts 
of  water,  2  jiarts  crystallized  chloride  of  iron,  2  parts  chloride  of 
antimonj',  and  1  part  gallic  acid,  and  apply  the  solution  with  a 
sponge  or  cloth  to  the  article,  and  dry  it  in  the  air.  Eepeat  this 
any  number  of  times  according  to  the  depth  of  color  which  it  is 
desired  to  jiroduce.  Wash  with  water,  and  dry,  and  finally  rub 
the  articles  over  with  boiled  linseed  oil.  The  metal  thus  receives 
a  brown  tint  and  resists  moisture.  The  chloride  of  antimony 
should  be  as  little  acid  as  possible. 

To  ornament  Gun  Barrels. — A  very  pretty  appearance 
is  given  to  gun  barrels  by  treating  them  with  dilute  nitric  acid 
and  vinegar,  to  which  has  been  added  sulphate  of  copper.  The 
metallic  copper  is  deposited  irregularly  over  the  iron  surface. 
Wa.sh,  oil,  ami  rub  well  with  a  hard  brush. 

To  remove  Rust  from  Iron.— yVeha.\e  never  seen  any 
iron  so  badly  scaled  or  incrusted  with  oxide,  that  it  could  not  be 
cleaned  with  a  solution  of  1  jjart  sulphiiric  acid  in  10  parts 
water.  Paradoxical  as  it  may  seem,  strong  suljshuric  acid  will 
not  attack  iron  with  anything  like  the  energy  of  a  solution  of  the 
same.  On  withdrawing  the  articles  from  the  acid  soliition  they 
should  be  dipped  in  a  bath  of  hot  lime-Mater,  and  held  there  till 
they  become  so  heated  that  they  will  dry  immediately  when 
taken  out.  Then,  if  they  are  rubbed  with  dry  bran  or  sawdust, 
there  will  be  an  almost  chemically  clean  surface  left,  to  which 
zinc  will  adhere  readily 

To  protect  Iron  from  Oxidization.— ^mong  the  many 
processes  and  preparations  for  preserving  iron  from  the  action  of 
the  atmosphere,  the  following  will  be  found  the  most  efficient  in 
all  cases  where  galvanization  is  imiaracticable  ;  and,  being  un- 
afi"ected  by  sea-water,  it  is  especially  applicable  to  the  bottom  of 
iron  ships,  and  marine  work  generally  :  Sulphur,  17  pounds  ; 
caustic  potash  lye  of  35^  Baume,  5  pounds  ;  and  copper  filings, 
1  pound.  To  be  heated  until  the  copper  and  sulphur  dissolve. 
Heat,  in  another  vessel,  tallow,  750  pounds,  and  turpentine,  150 
pounds,  until  the  tallow  is  liquefied.  The  compositions  are  to 
be  mixed  and  used  same  as  paint. 


214  PRACTICAL   MECHAXICAL   RECEIPTS. 

To  scour  Cast  Iron,  ZinCf  or  Brass.— Cast  iron,  zinc, 
and  brass  surfaces  can  be  scoured  -with  great  economy  of  labor, 
time,  and  material,  by  using  either  glycerine,  stearine,  naptha- 
line,  or  creosote,  mixed  with  dilute  sulphuric  acid. 

Wood  Chips,  Bark,  &c.,  as  a  Preventive  of  In- 
crustation in  Boilers.— Caiechw,  nut-galls,  oak  bark, 
shavings  and  sawdust,  tan  bark,  tormentilla  root,  mahogany, 
logwood,  etc.  These  substances  all  contain  more  or  less  tannic 
ac?d,  associated  with  soluble  extractive  and  coloring  matters. 
When  they  are  introduced  into  the  boiler,  the  soluble  constitu- 
ents are  dissolved  by  the  water,  and  basic  tannate  of  lime  is 
formed,  which  separates  as  a  loose  deposit,  and  does  not  adhere 
to  the  sides  of  the  boiler.  It  is  preferable  to  use  the  aqueous  ex- 
tract, as  sawdust,  chips,  etc.,  are  liable  to  find  their  way  into  the 
cocks  and  tubes,  although  they  act  mechanically,  receiving  in- 
crustations which  would  otherwise  fasten  themselves  on  the  sides 
of  the  boiler.  In  selecting  one  of  these  substances,  the  princi- 
pal object  is  to  secure  the  largest  quantity  of  tannic  acid  and 
soluble  extractive  matter  for  the  lowest  price.  Some  of  these 
substances  are  said  to  be  very  effective,  i  pound  of  catechu  being 
sufficient  for  100  cubic  feet  of  water.  F"rom  4  to  6  pounds  of  oak 
chips  have  been  recommended  per  horse-power,  or  i  bushel 
mahogany  chii)s  for  every  10  horse-power. 

Mucilaginous   Suhstanees  as    Freveutives.—Voia^ 

toes,  starch,  bnm,  linseed  meal,  gum,  dextrine,  Irish  moss,  slip- 
pery elm,  marshmallow  root,  glue,  etc.  These  substanc&s  form, 
sooner  or  latter,  a  slimy  liquid  in  the  boiler,  which  prevents 
more  or  less  completely  the  settling  and  hardening  of  the  de- 
posits. Some  of  them  may  even  hold  the  lime  and  magnesia  in 
solution.  Potatoes  have  been  used  for  many  years,  wherever 
steam-engines  are  employed  ;  half  a  peck  or  a  peck  are  thrown 
into  t'le  boiler  weekly.  Linseed  meal  mixe  1  with  chopped  straw 
was  employ(!d  on  a  German  railway,  a  peck  at  a  time  being  in- 
troduced into  each  boiler.  Some  writrrs  object  to  these  or- 
ganic substances,  on  the  ground  that  they  are  liable  to  cause 
frothing. 

Sacchariue  Mutter  as  Preventives.  — ^\\ga.r,  mola.s- 
ses,  corn  or  potato  sirup.  Both  cane  an;l  grap«!  sugar  form  .solu- 
ble compounds  with  lime  salts,  and  cous(;(inently  prevent  tJieir 
separation  as  incrustations.  One  engineer  found  that  li>  pounds 
of  brown  sugar  protected  his  boiler  for  two  mouths  ;  another, 
that  G  pounds  of  corn  .starch  sirup  had  a  similar  effect.  Another 
used  moliiss&s  with  success,  introducing  a  gallon  at  a  time. 

Fattif  Siiltxfuuces  us  Preventives.  Ono  writer  used 
whale  oil  to  jin  vent  incrustations,  '2  or  3  gallims  at  a  time. 
Others  smear  tlio  inside  of  the  boiler  with  various  mixtures  of  a 
fatty  character.  Stearine,  mixed  with  wood  ashes,  charcoal,  and 
tar,  hivs  been  recommendi.d;  or  tallow,  with  soap  and  charcoal 
diluted  with  oil  or  tar.  or  tillow  and  grajjliite.  This  plan  cf)ul  I 
not  well  be  apjilii'l  to  a  locomotive  l)oiler  witli  its  numerous 
tabus,  even  though  il  should  prove  effective  in  cylinder  boilers. 


PRACTICAL   MECHANICAL  RECEIPTS.  215 

To  protect  Iron  from  Rust. — A  mastic  or  covering  for 
this  purpose,  proposed  by  M.  Zeni,  is  as  follows:  IVIix  80  parts 
pounded  brick,  passed  through  a  silk  sieve,  with  2U  parts  lith- 
arge; the  vrhole  is  then  rubbed  up  by  the  muUer  with  linseed 
oil,  so  as  to  form  a  thick  paint,  which  may  be  diluted  with  spirits 
of  turpentine.  Before  it  is  applied  the  iron  should  be  well 
cleaned.  From  an  experience  of  two  years  upon  locks  exposed  to 
the  air,  and  wateresl  daily  with  salt  water,  after  being  covered 
with  two  coats  of  this  mastic,  the  good  effects  of  it  have  been 
thoroughlj"  proved. 

To  jirevent  the  Decatj  of  Iron  Rail inf/s.— 'Every  one 

must  have  noticed  the  destructis-e  combination  of  lead  and  iron, 
from  railings  being  fixed  in  stone  with  the  former  metal.  The 
reason  for  this  is,  that  the  oxygen  of  the  atmosphere  keeps  up  a 
galvanic  action  bet\v\-LU  tiie  two  metals.  This  waste  may  be  pre- 
vented by  substituting  zinc  for  lead,  in  which  case  the  galvanic 
influence  would  be  inverted;  the  whole  of  its  action  would  fall 
on  the  zinc  ;  the  one  remaining  uninjured,  the  other  nearly  so. 
Paint  formed  of  the  oxide  of  zinc,  for  the  same  reason  preserves 
iron  exposed  to  the  atmosphere  infinitely  better  than  the 
ordinary  jDaint  composed  of  the  oxide  of  lead. 

To  clean  Steel  and  Jroii.— Make  1  ounce  soft  soap  and 
2  ounces  emery  into  a  paste  ;  rub  it  on  tlie  article  with  wash- 
leather  and  it  will  have  a  brilliant  polish.  Kerosene  oil  will  also 
clean  steel. 

To  convert  Iron  into  Steel.— This  is  usually  done  by 
the  process  of  cementation,  producing  what  is  termed  blistered 
steel.  At  the  bottom  of  a  trough  about  2  feet  square  and  14 
feet  long,  usually  formed  of  fire-clay,  is  placed  a  layer,  rdjout 
2  inches  thick,  of  a  cement  composed  of  10  parts  charcoal  and  I 
part  ashes  and  common  salt  ;  upon  this  is  laid  a  tier  of  thin  iron 
bars  about  J  inch  apart  ;  between  and  over  them,  a  layer  of 
cement  is  spread,  then  a  second  row  of  bars,  and  so  on,  alternate- 
ly, until  the  trough  is  nearly  full;  lastly  a  layer  of  cement  cover- 
ed with  moist  sand  and  a  close  cover  of  fire-tiles,  so  as  to  exclude 
the  air.  The  trough  is  exposed  to  the  heat  of  a  coal  fire,  until  a 
full  red  heat,  about  2')00°  Fahr.,  is  obtained  and  kept  up  steadily 
for  about  7  days.  A  hole  is  left  in  the  end  of  the  trough,  to 
allow  of  a  bar  being  drawn  out  for  examination.  When  a  bar, 
on  being  withdrawn  an  1  broken,  has  ac(^nired  a  crystalline 
texture,  the  metal  is  allowed  to  cool  down  gradually,  some  days 
being  allowed  for  this,  and  the  charge,  when  cool,  withdrawn  from 
the  trough.  The  bars  will  be  found  covered  with  large  blisters, 
hence  the  name  of  the  process,  and  increased  about  -^i^  in  weight. 
The  steel  is  now  sufficiently  good  for  files  and  coarser  tools,  but 
for  finer  instruments  several  varieties  of  finer  steel  are  required. 

Steel  made  from  Iron  ,Srrrf;>.s\— Take  iron  scraps  in 
small  pieces,  put  40  pounds  in  a  crucible,  with  8  ounces  charcoal, 
and  4  ounces  black  oxide  of  manganese  ;  expose  the  whole  1  j 
hours  to  a  high  heat  and  run  into  moulds. 


216  PRACTICAL   MECHANICAL   RKCEIPTS. 

To  malic  Sheaf  S^ec?.— This  is  produced  by  cutting  up 
bars  of  blistered  steel,  into  lengths  of  30  inches,  and  binding 
them  in  bundles  of  8  or  9  by  a  ring  of  steel,  a  rod  being  fixed 
for  a  handle.  These  are  brought  to  a  welding  heat,  and 
welded  together  under  a  tilt  hammer.  The  binding  ring  is  then 
removed;  and,  after  reheating,  tin  mass  is  forged  solid,  and  ex- 
tended into  a  bar.  In  cases  where  this  operation  is  repeated, 
the  steel  is  called  double-shear  steel. 

To  make  Cast  Sf re?.— Cast  steel  is  the  best  variety  for 
all  fine  cultiug  tools.  This  is  a  mixture  of  scraps  of  different 
varieties  of  blistered  steel,  collected  together  in  a  good  refractory 
clay  crucible;  upon  this  a  cover  is  luted,  and  it  is  exposed  to  an 
intense  heat  in  a  blast  furnace  for  3  or  1  hours.  The  contents 
are  then  run  into  moulds.  After  being  subjected  to  the  blows 
of  a  tilt-hammer,  the  cast  steel  is  ready  for  use. 

To  keejt  Polislied  Iron  Work  brhfltt— Common  resin 
melted  with  a  little  gallipoli  oil  and  spirits  of  turpentine  has 
been  found  to  answer  very  well  for  preserving  polislied  iron  work 
bright.  The  proportions  should  be  such  as  to  form  a  coating 
whudi  will  adhere  firmly,  not  chip  off,  and  yet  admit  of  being 
easily  detached  by  cautious  scra]>ing. 

To  take  Proof -Impressions  of  Seals  and  Stamps. 

—For  this  purpose  the  very  best  sealing-wax  is  m.lted  as  usual 
by  a  flame,  and  carefully  worked  on  the  surface  to  which  it  is 
applied,  until  perfectly  even;  the  stamp  is  then  firmly  and  evenly 
pressed  into  it.  The  fiame  of  a  spirit  lamp  is  preferable,  having 
no  tendency  to  blacken  the  wax.  A  beautiful  dead  appearance  is 
given  to  the  impression  by  dusting  the  stamp  before  using  it 
with  a  finely-powdered  pigment  of  the  same  color  as  the  wax  ; 
thus,  for  vermilion  sealing-wax,  powdered  vermilion,  &c. 

To  hliie  Steel.  -T\\o  mode  emidoyed  in  blueing  steel  is 
merely  to  subject  it  to  heat.  The  dark  blue  is  produced  at  a 
temperature  of  GOO',  the  full  blu(!  at  r>0(r,  and  the  blue  at  550°. 
The  steel  must  be  finely  polished  on  its  surface,  and  then  ex- 
posed to  a  uniform  degree  of  heat.  Accordingly,  there  arc  throe 
ways  of  coloring:  first,  liy  a  flame  producing  no  soot,  as  spirit  of 
wine;  secondly,  by  a  hot  plate  of  iron;  and  thirdly,  by  wood 
ashes.  As  a  very  regular  degree  of  heat  is  necessary,  wood  ashes 
for  fine  work  bear  the  preference.  The  work  must  be  covered 
over  with  them,  and  canfutlv  watched;  when  the  color  is  siilfi- 
ciently  heiglitened,  the  workis  perfect.  This  color  is  occasion- 
ally tiiken  off  with  a  very  dilute  muriatic  acid. 

To  reiiiore  Scale  fnun  Steel. --'^(•■.xhi  may  bo  removed 
from  steel  articles  by  i)ickliug  in  water  with  a  little  stilphnria 
acid  in  it,  and  when  the  scale  is  loosened,  brushing  with  sand 
and  a  stiff  brush. 

To  temper  Spiral  Sprhnjs.  Ibat  to  a  cherry  red  in  n 
charcoiil  firr,  un.l  liard.n  in  oil.  To  temper,  blaze  oflF  the  oil 
three  times,  the  samo  as  for  Hat  springs. 


PRACTICAL   MECHANICAL   RECEIPTS.  217 

Cautions  on   the  use  of  Lead  for  Cisterns,  tCc. — 

Ordinary  water,  wLicli  abounds  in  mineral  salts,  may  be  safely 
kept  in  leaden  cisterns  ;  but  distilled  and  rain  water,  and  water 
that  contains  scarcely  any  saline  matter,  speedily  corrode,  and 
dissolve  a  portion  of  lead,  when  kept  in  vessels  of  that  metal. 
When,  however,  leaden  cisterns  have  iron  or  zinc  fastenings  or 
braces,  a  galvanic  action  is  stt  up,  the  preservative  power  of 
saline  matter  ceases,  and  the  water  si^eedily  becomes  contami- 
nated Avith  lead.  Water  containing  free  carbonic  acid  also  acts 
on  lead  ;  and  this  is  the  i-eason  why  the  water  of  some  sjirings, 
kept  in  leaden  cisterns,  or  raised  by  leaden  pumps,  possesses 
unwholasome  properties.  Free  carbonic  acid  is  evolved  during 
the  fermentation  or  decay  of  vegetable  matter,  and  hence  the 
propriety  of  preventing  the  leaves  of  trees  falling  into  water- 
cisterns  formed  of  lead. 

To  test  the  Richness  of  Lead  Oi'es.— Lead  ores,  or 
galena,  may  be  tested  in  different  ways.  The  wet  way  is  as  fol- 
lows: Digest  100  grains  of  the  ore  in  sufficient  nitric  acid  diluted 
with  a  little  water,  apply  heat  to  expel  any  excess  of  acid,  and 
largelj'  dilute  the  remainder  with  distilled  water.  Next  add 
dilute  hydrochloric  acid,  by  drops,  as  long  as  it  occasions  a  pre- 
cipitate, and  filter  the  whole,  after  being  moderately  heated,  upon 
a  small  paper  filter.  Treat  the  filtered  liquid  with  a  stream  of 
suli^hureted  hydrogen  ;  collect  the  black  precipitate,  wash  it, 
and  digest  it  in  strong  nitric  acid;  when  entirely  dissolved,  pre- 
cii:)itate  the  lead  with  sulphuric  acid  dropped  in  it,  evaporate  the 
precipitate  to  dryness,  the  excess  of  sulphuric  acid  being  ex- 
pelled by  a  rather  strong  heat  applied  toward  the  end.  The  dry 
mass  should  be  M^ashed,  dried,  and  exposed  to  slight  ignition  in 
a  porcelain  crucible.  The  resulting  dry  sulphate  is  equal  to  .G8 
per  cent,  of  its  weight  in  lead. 

To  anneal  Steel. — For  a  small  quantity.  Heat  the  steel  to 
a  cherry  red  in  a  charcoal  fire,  then  bury  it  in  sawdiist,  in  an  iron 
box,  covering  the  sawdust  with  ashes.  Let  it  stay  until  cold. 
For  a  larger  quantity,  and  when  it  is  required  to  be  very  soft,  pack 
the  steel  with  cast  iron  (lathe  or  planer)  chips  in  an  iron  box,  as 
follows:  Having  at  least  i  or  |  inch  in  depth  of  chips  in  the  bot- 
tom of  the  box,  put  in  a  laj'er  of  steel,  then  more  chips  to  fill 
sjiaces  between  the  steel,  and  also  the  ^  or  J  inch  space  between 
the  sides  of  box  and  steel,  then  more  steel ;  and  lastly,  at  least  1 
inch  in  depth  of  chips,  well  I'ammed  down  on  top  of  the  steel. 
Heat  to  and  keep  at  a  red  heat  for  from  2  to  i  hours.  Do  not 
disturb  the  box  until  cold. 

To  straighten  Hardened  Steel.— To  straighten  a  piece 
of  steel  already  hardened  and  tempered,  heat  it  lightly,  not 
enough  to  draw  the  temj^er,  and  you  may  straighten  it  on  an 
anvil  with  a  hammer,  if  really  not  dead  cold.  It  is  best,  how- 
ever, to  straighten  it  between  the  centres  of  a  lathe,  if  a  turned 
article,  or  on  a  block  of  wood  with  a  mallet.  Warm,  it  jdelds 
readily  to  the  blows  of  the  mallet,  but  cold,  it  would  break  like 
glass. 

10 


21S  PRACTICAL   MECHANICAL   RECEIPTS. 

To  prevent   the    Corrosion  of   Copper  and  otlter 

3r<f(ffs. — The  best  rneaus  of  i^roventing  corrosion  of  metals  is 
to  dip  the  articles  first  into  a  very  dilute  nitric  acid,  immerse 
them  afterward  in  linseed  oil,  and  allow  the  excess  of  oil  to 
drain  off.  By  this  i^rocess  metals  are  effectually  prevented  from 
rust  or  oxidation. 

To  elean  Coppers  and  Tins.— These  are  cleaned  with 
a  mixture  of  rotten  stone,  soft  soap,  and  oil  of  turpentine,  mixed 
to  the  consistency  of  stiff  putty.  The  stone  should  be  powdered 
very  fine  and  sifted;  and  a  quantity  of  the  mixture  may  be  made 
Buflicient  to  last  for  a  long  while.  The  articles  should  first  be 
washed  with  hot  water,  to  remove  grease.  Then  a  little  of  the 
above  mixture,  mixed  with  water,  should  be  rubbed  over  the 
metal  ;  then  rub  oft"  briskly,  \\-ith  dry  clean  rag  or  leather,  and  a 
beautiful  jiolish  will  be  obtained.  When  tins  are  much  blacken- 
ed by  the  fire  they  should  be  scoured  with  soai^,  water,  and  fine 
sand. 

To  find  the  pereentar/e  of  Lead  in  I^ead  Ores.— 
This  can  be  done  by  applying  the  test  in  the  wet  way  and  multi- 
plying the  weight  of  the  product  obtained  in  grains  by  .08.  It 
may  also  be  found  in  the  dry  way,  as  follows  :  Plunge  a  conical 
wrought-iron  crucible  into  a  blast  furnace,  raised  to  as  high  a 
heat  as  possible  ;  when  the  crucible  has  become  of  a  dull  red 
heat,  introduce  into  it  1,0G0  grains  galena  (lead  ore)  reduced  to 
powder,  and  stir  it  gently  with  a  piece  of  stiff  iron  wire  flattened 
at  the  end.  This  wire  must  never  be  suff"ered  to  ge'«,  red  hot.  To 
prevent  the  ore  from  adhering,  after  3  or  4  minutes,  cover  up  the 
crucible  ;  and  when  at  a  full  cherry-red  heat,  add  2  or  3  spoon- 
fuls of  reducing  flux,  and  bring  to  a  full  white  heat  ;  in  12  to  15 
minutes,  after  having  scraped  down  tlie  scoria,  etc.,  from  the 
sides  of  the  crucible,  into  the  melted  mass,  tlie  crucible  should 
be  removed  from  the  tire,  and  the  contents  tilted  into  a  small 
brass  mould,  observing  to  run  out  the  metal  free  from  scoriii,  by 
raking  tlie  latter  back  with  a  piece  of  green  wood.  The  scoria  is 
then  reheated  in  the  crucible  with  },  spoonful  of  fiux,  and  this 
second  reduction  added  to  tlie  first.  1  lie  w<iglit  in  ;  rains  of  the- 
metal  ol>t:une(l,  divided  by  10,  gives  t!ie  percentage  of  metallic 
lead  in  the  sample  of  ore. 

To  temper  PielkS.—MUv  working  the  steel  carefully,  pre- 
pare a  bath  of  lea  1  heated  to  the  boiling  point,  whicli  will  be 
indicated  by  a  slight  agitation  of  the  surfiu^e.  In  it  jjlaco  the 
end  of  the  pick  to  the  dcjjth  of  \\  inches,  until  lieate<l  to  the 
temperature  of  the  l.-ad.  then  i)lunge  inuncdiately  in  <dear  cold 
•water.  The  temper  will  be  just  right,  if  the  bath  is  at  the  tem- 
])erature  nMjuirerl.  The  princi])al  ri(piisities  in  making  mill 
l)icks  are:  First,  get  good  steel.  Second,  work  it  at  a  low  heat; 
most  l)liu;ksmitlis  injure  steel  by  overheating.  Third,  heat  for 
temj)rring  without  direct  exposure  to  the  firi>.  1  he  lead  bath 
iicts  merely  as  protection  against  the  heat,  which  is  almost  always 
too  great  to  temper  welL 


PRACTICAL  MECHANICAL  RECEIPTS.  219 

To  hliie  sin^ll  Steel  Articles. — Make  a  box  of  sheet  iron, 
fill  it  with  sand,  and  subject  it  to  a  great  heat.  The  articles  to 
be  blued  must  be  finished  and  well  polished.  Immerse;  the  arti- 
cles m  the  sand,  keeping  watch  of  them  until  they  are  of  the 
right  color,  when  they  should  be  taken  out  and  immersed  in  oil. 

To  restore  burnt  Cast  Steel.— Take  IJ  lbs.  borax,  k  lb. 
sal-ammoniac,  4  lb.  prussiate  of  potash,  1  oz.  resin.  Pound  the 
above  fine,  add  a  gill  each  of  water  and  a'cohol.  Put  in  an  iron 
kettle,  and  boil  until  it  becomes  a  paste.  Do  not  boil  too  long, 
or  it  will  become  hard  on  cooling. 

To  temper  I>riUs. — Heat  the  best  steel  to  a  cherry  red, 
and  hammer  until  nearly  cold,  forming  the  end  into  the  requisite 
flattened  shape,  then  heat  it  again  to  a  cherry  red,  and  plunge  it 
into  a  lump  of  resin  or  into  quicksilver.  A  solution  of  cyanide 
of  potassium  in  rain-water  is  sometimes  used  for  the  tempering 
plunge-bath,  but  it  is  not  as  good  as  quicksilver  or  resin. 

To  temper  Gravers. — These  may  be  tempered  in  the  same 
way  as  drills  ;  or  the  red-hot  instrument  may  be  pressed  into  a 
piece  of  lead,  in  which  a  hole  about  \  an  inch  deep  has  been  cut 
to  receive  the  graver  ;  the  lead  melting  around  and  inclosing  it 
will  give  it  an  excellent  temper. 

To  temper  Old  Files. — Grind  out  the  cuttings  on  one 
side,  until  a  bright  surface  is  obtained;  then  damp  the  surface 
with  a  little  oil,  and  lay  the  file  on  a  piece  of  red-hot  iron,  bright 
side  upward.  In  about  a  minute  the  bright  surface  will  begin 
to  turn  yellow,  and  when  the  yellow  has  deej)ened  to  about  the 
color  of  straw,  plunge  in  cold  water. 

To  maJxe  Polished  Steel  Stratv  Color  or  Slue.— The 

surface  of  polished  steel  acquires  a  pale  straw  color  at  460°  Fahr., 
and  a  uniform  deep  blue  at  580"^  Fahr. 

liath  for  harden ittf/  PieJxS. — Take  2  gallons  rain-water, 

I  ounce  corrosive  sublimate,  1  of  sal-ammoniac,  1  of  saltpetre, 

II  pints  rock  salt.  The  picks  shouhl  be  heated  to  a  cherry  red, 
an  1  cooled  in  the  bath.  The  salt  gives  hardness,  and  the  other 
ingredients  toughness  to  the  steel  ;  and  they  will  not  break,  if 
they  are  left  without  drawing  the  temper. 

Composition  for  temperinff  Cast- Steel  Mill  Pieks. 

To  .S  gallons  of  water,  add  3  ounces  each  nitric  acid,  spirits  of 
hartshorn,  sulphate  of  zinc,  sal-ammoniac,  and  alum;  6  ounces 
salt,  with  a  double  handful  of  hoof-parings;  the  steel  to  be  heat- 
ed a  dark  cherry  red.  It  must  be  kept  corked  tight  to  prevent 
evaporation. 

Tempering  Steel  — Mr.  N.  P.  Ames,  late  of  Chicopee,  Mass., 
after  expending  mvich  time  and  money  in  experiments,  found 
that  the  most  successful  means  of  tempering  swords  and  cirtlasses 
that  would  stand  the  United  States  Government  test,  was  by 
heating  in  a  charcoal  fire,  hardening  in  pure  spring  water,  and 
drawing  the  temper  in  charcoal  flame. 


220  PRACTICAL   MECHANICAL   RECEIPTS. 

Engraving  3Hxttire  for  Writing  on  Sfc«r —Sulphate 
of  copper,  1  ounce;  sal-ammoniac,  ^  ounce;  pulverize  separately, 
adding  a  little  vermilion  to  color"  it,  and  mix  with  \\  ounces 
vinegar.  Eub  the  steel  with  soft  soap  and  write  with  a  clean 
hard  pen,  without  a  slit,  dipped  in  the  mixture. 

To  nwhe  Edge-Tools  from  Cast  Steel  and  Iron.— 

This  method  consists  in  fixing  a  clean  piece  of  wrought  iron, 
brought  to  a  welding  heat,  in  the  centre  of  a  mould,  and  then 
pouring  in  melted  steel,  so  as  entirely  to  envelop  the  iron;  and 
then  forging  the  mass  into  the  shape  required. 

Cement  for  fixing  Metal  to  Leather.— ^Yash  the  metal 
in  hot  gelatine,  steep  the  leather  in  hot  gall-nut  infusion,  and 
unite  while  hot. 

Cenhent  for  Gai^  Iietort.s.—\  new  cement,  especially 
adapted  to  Vae  retorts  of  gas-works,  is  very  warmly  recommend- 
ed in  a  German  gas-light  journal.  It  consists  of  fincly-i^owdered 
barytes  and  a  soluble  watei'-glass  ;  or  the  barytes  and  a  solution 
of  borax.  The  joints  are  to  be  coated  several  times  with  this 
cement,  by  means  of  a  brush.  The  addition  of  two-thirds  of  a 
part  of  clay  improves  the  cement,  and  the  retorts  will  then  stand 
a  red  heat  very  well.  Instead  of  the  water-glass,  a  solution  of 
borax  may  bo  used,  or  even  finely  powdered  white  glass. 

Cement  for  Cloth,  Leather,  or  Belting.— Tnke  ale,  1 
pint ;  best  Ilussia  isinglass,  2  oui^ccs  ;  jnit  them  into  a  common 
glue  kettle  and  boil  uutil  the  isinglass  is  dissolved  ;  then  add  4 
ounces  best  glue,  and  dissolve  it  witli  the  other;  then  slowly  add 
IJ  ounces  boiled  linseed  oil,  stirring  all  the  time  while  adding 
and  until  well  mixed.  When  cold  it  will  resemble  india-rubber. 
To  use  this,  dissolve  what  is  needed  in  a  suitable  quantity  of  ale 
to  the  consistence  of  thick  glue.  It  is  applicable  for  leather,  for 
harness,  bands  for  machinery,  cloth  belts  for  cracker  machines 
for  bakers,  Ac,  Ac.  If  for  leather,  shave  off  as  if  for  sewing, 
apply  the  cement  with  a  brush  while  hot,  laying  a  weight  to 
keep  each  joint  firmly  for  G  to  10  liours,  or  over  night. 

Cement  for  Lit/ther  Jielting.—Tiike  of  common  glue 
an  I  American  isinglass,  ecpial  parts ;  place  them  in  a  glue-pot 
an<l  add  water  sullicierit  to  just  cover  the  wliole.  Let  it  soak  10 
hours,  then  bring  the  whole  to  a  boiling  heat,  and  add  pure  tan- 
nin until  the  wliole  becomes  ropy  or  appears  like  the  white  of 
eggs.  Apply  it  warm.  Bntf  the  gniin  off  the  leather  where  it  is 
to  be  cemented;  rub  the  joint  surfaci-s  solidly  together,  let  it  dry 
a  few  hours,  and  it  is  ready  for  use  ;  und,  if  ])roperly  put  to- 
gether, it  will  not  need  riveting,  as  the  cement  is  nearly  of  the 
same  nature  as  tlu;  leather  itself.  Wo  know  of  no  cement  belter 
cither  for  emery  wheels  or  emery  belts  than  the  best  glue.  In  an 
experience  of  fifteen  years  wo  never  found  anything  superior. 

Cement  for  fi.ring  Metal  to  Marble,  Stone,  or 
ft  (nt;l.  —Mix  together  4  parts  Ciirpcnters'  glue  and  1  part  Venice 
f.irpentino. 


PRACTICAL   MECHANICAL   RECEIPTS.  221 

Cement  to  stop  Flaws  or  Crticks  in  Wood  of  any 

Color.— Fnt  any  quantity  of  fine  sawdust,  of  the  same  wood 
the  work  is  made  with,  into  an  earthen  pan,  and  pour  boiling 
•water  on  it,  stir  it  well,  and  let  it  renain  for  a  week  or  ten  days, 
occasionally  stirring  it;  then  boil  it  for  some  time,  and  it  -will  be 
of  the  consistence  of  pulp  or  paste  ;  put  it  into  a  coarse  cloth, 
and  squeeze  all  the  moisture  from  it.  Keep  for  use,  and,  when 
•wanted,  mix  a  suflicient  quantity  of  thin  glue  to  make  it  into  a 
paste ;  rub  it  well  into  the  cracks,  or  fill  up  the  holes  in  the 
work  with  it.  When  quite  hard  and  dry,  clean  the  work  off,  and, 
if  carefully  done,  the  imperfection  will  be  scarcely  discernible. 

To  cement  Cloth  to  Polished  Metal.— Cloih.  can  be 
cemented  to  polished  iron  shafts,  by  first  giving  them  a  coat  of 
best  white  lead  paint ;  this  being  d-ied  hard,  coat  with  best  Ilus- 
sian  glue,  dissolved  in  water  containing  a  little  vinegar  or  acetic 
acid. 

Gut  fa-Perch  a  Cement. — This  highly  recommended  ce- 
ment is  made  by  molting  together,  in  an  iron  pun,  2  parts  com- 
mon pitch  and  1  part  gutta-percha,  stirring  them  well  together 
until  thoroughly  incorporated,  and  then  pouring  the  liquid  into 
cold  water.  ^Vhen  cold  it  is  black,  solid,  and  elastic;  btit  it 
softens  with  heat,  and  at  lOJ"^  Fahr  is  a  thin  fluid.  It  may  be 
used  as  a  soft  paste,  or  in  the  liquid  state,  and  answers  an  excel- 
lent p-arx^oSfe  in  cementing  metal,  glass,  porcelain,  ivory,  &c.  It 
may  be  used  instead  of  putty  for  glazing  windows. 

To  dis.<oli'e  Ind ia-Ttuhher  for  Cement,  tC'C. — India- 
rubber  dissolves  readilj'  in  rectified  sulphuric  ether,  which  has 
been  washed  with  water  to  remove  alcohol  and  acidity  ;  also  in 
chloroform.  These  make  odorless  solutions,  but  are  too  expen- 
sive for  general  use.  The  gum  dissolves  easily  in  bisulphuret  of 
carbon  ;  or  a  mixture  of  Qi  parts  bisulphuret  of  carbon  and  6 
parts  absolute  alcohol ;  also  in  caoutchoucine.  These  dissolve 
the  gum  rapidly  in  the  cold,  and  leave  it  unaltered  on  evapora- 
tion ;  they  have  a  disagreeable  odor,  but  they  leave  the  india- 
rubber  in  better  condition  than  most  other  solvents.  Oil  of  tur- 
pentine, rendered  pyrogenous  by  absorbing  it  with  bricks  of 
porous  ware,  and  distilling  it  without  water,  and  treating  the 
product  in  the  same  way,  is  also  used  for  this  puii^ose.  It  is 
stated  that  the  solution  on  evaporation  does  not  leave  the  caout- 
chouc in  a  sticky  state.  Another  method  is  to  agitate  oil  of  tur- 
pentine rep'atedly  Avith  a  mixture  of  equal  weights  of  sulphuric 
acid  and  water,  and  afterward  expose  it  to  the  sun  for  some 
time.  Benzole,  rectified  mineral  or  coal  tar  naphtha,  and  oil  of 
turpentine  reduce  the  gum  slowly  by  long  digestion  and  tritura- 
■  tion,  with  heat,  forming  a  glutinous  jelly  which  dries  slowly,  and 
leaves  the  gum  when  drj',  very  much  reduced  in  hardness  and 
elasticity.  Xlie  fats  and  fixed  oils  combine  readily  with  india- 
rubber  by  boiling,  forming  a  permanently  glutinous  paste.  In- 
dia-rubber is  rendered  more  readily  soluble  by  first  digesting  it 
with  a  solution  of  carbonate  of  soda,  or  water  of  ammonia. 


222  PRACTICAL   MECHANICAL   RECEIPTS. 

Cetnent  for  coating  Acid  Troiif/hs.— Melt  together  ". 
part  pitch,  1  part  resin,  and  1  part  j^h^ster  of  Paris  (perfectly 
dry). 

Cement  for  Uniting  Sheet  Gutta-Percha  to 
Leather. — For  uniting  sheet  gutta-percha  to  leather,  as  soles 
of  shoes,  etc. :  Gutta-percha,  50  pounds  ;  Venice  turpentine,  4'J 
pounds  ;  shellac,  -1  pounds  ;  caoutchouc,  1  pound  ;  liquid  storax, 
5  pounds.  In  making  the  cement,  the  Venice  turpentine  should 
be  hrst  heated  ;  then  the  gutta-percha  and  the  shellac  should  be 
added  ;  the  order  in  which  the  other  materials  are  added  is  not 
important.  Care  should  be  taken  to  incorporate  them  thorough- 
ly, and  the  heat  should  be  regulated,  so  as  not  to  burn  the  mix- 
ture. 

Case-Hardening  is  the  operation  of  giving  a  surface  of 
Bteel  to  pieces  of  iron,  by  which  they  are  rendered  capable  ol 
receiving  great  external  hardness,  while  the  interior  portion 
retains  all  the  toughness  of  good  wrought  iron.  This  is  accom- 
plished by  heating  the  iron  in  contact  with  animal  carbon,  in 
close  vessels.  The  articles  intended  to  be  case-hardened  are  put 
into  the  box  with  animal  carbon,  and  the  box  made  air-tight  by 
luting  it  with  clay.  They  ai-e  then  placed  in  the  fire  and  kept  at 
a  light-red  heat  for  any  length  of  time,  according  to  the  depth 
required.  In  half  an  hour  after  the  box  and  its  contents  have 
been  heated  quite  through,  the  hardness  will  scarcely  be  the 
thickness  of  a  half  dime;  in  an  hour,  double;  and  so  forth,  until 
the  desired  depth  is  acquired.  The  box  is  then  taken  fiom  the 
fire,  and  the  contents  emj^tied  into  i)ure  cold  water.  They  can 
then  be  taken  out  of  the  water  and  dried  (to  keep  thom  from 
rusting),  by  riddling  tliem  in  a  sieve  with  some  dry  sawdust ; 
and  they  are  then  ready  for  polishing.  Case-hardening  is  a 
BuiJerficial  conversion  of  iron  into  steel.  It  is  not  always  merely 
for  economy  that  iron  is  case-hardened,  but  for  a  multitude  of 
things  it  is  i)referablc  to  steel,  and  answers  the  purpose  better. 
Delicate  articles,  to  keep  from  blistering  while  heating,  may  bo 
dipped  into  a  powder  of  burnt  leather,  or  bones,  or  other  coaly 
animal  matter. 

To  Cfisc-harden. — Make  a  paste  with  a  concentrated  solu- 
tion of  pnissiate  of  potasli  and  loam,  and  coat  the  iron  there- 
with ;  then  expose  it  to  a  strong  red  heat,  and  when  it  has  fallen 
to  a  dull  red,  plunge  the  whole  into  cold  water. 

J'o  cane-harden  I^olislted  Iron. — The  iron,  previous- 
ly polislied  and  fiiiislu'd,  is  to  bo  heated  to  a  bright  red  and  rub- 
bod  or  K])rinkle(l  over  with  prussiato  of  potash.  As  soon  as  tho 
]>russiat(:  app-itrs  to  be  deeomi)osed  and  dissipated,  plunge  tho 
articl(!  into  cold  water.  Wlien  the  j)rocess  of  case-hardiiiing  has 
been  well  (conducted,  the  surface  of  tlio  metal  j)roves  sullieiently 
liard  to  resist  a  tile;.  Tlie  last  two  ])lans  are  a  great  impr<iveui<nt 
upon  the  common  method.  IJy  tins  apj)lioation  ofthe  i)russint(", 
as  in  the  last  rticeipt,  any  part  of  a  piece  of  iron  may  bo  case- 
hardened,  without  interfering  with  the  rest. 


PRACTICAL  MECHANICAL  RECEIPTS.  223 

To  case-luirdeii  with  Charcoal. — The  goods,  finished 
in  every  resiject  but  i^olishing,  are  put  into  an  iron  box,  and 
covered  with  animal  or  vegetable  charcoal,  and  cemented  at  a 
red  heat  for  a  period  varying  with  the  size  and  descriiJtion  of 
the  articles  operated  on. 

Moxon's  Method  of  Case-Hardeninff. —Co-w's  horn 
or  hoof  is  to  be  baked  or  thoroughly  dried  and  piilverized,  in 
order  that  more  may  be  got  into  the  box  with  the  articles.  Or 
bones  reduced  to  dust  answer  the  same  purjDose.  To  this  add  an 
equal  quantitj'  of  bay  salt ;  mix  them  with  stale  chamber-lye,  or 
'white  wine  vinegar;  cover  the  iron  with  this  mixture,  and  bed  it 
in  the  same  in  loam,  or  inclose  it  in  an  iron  box  ;  lay  it  on  the 
hearth  of  the  forge  to  dry  and  harden  ;  then  put  it  into  the  fire, 
and  blow  till  the  lump  has  a  blood-red  heat,  and  no  higher,  lest 
the  mixture  be  burnt  too  much.  Take  the  iron  out,  and  immerse 
it  in  water. 

Improved  Proeefts  of  Hardening  Steel. — Articles  man- 
ufactured of  steel  for  the  purj^oses  of  cutting,  are,  almost  with- 
out an  exception,  taken  from  the  forger  to  the  hardener  without 
undergoing  any  intermediate  process  ;  and  such  is  the  accus- 
tomed routine,  that  the  mischief  arising  has  escaped  obseiwation. 
The  act  of  forging  produces  a  strong  scale  or  coating,  which  is 
spread  over  the  whole  of  the  blade  ;  this  scale  or  coating  is  un- 
equal in  substance,  varying  in  j^roportion  to  the  degree  of  heat 
communicated  to  the  stoel  in  forging ;  it  is  almost  impenetrable 
to  the  action  of  water  when  immersed  for  the  purpose  of  harden- 
ing. Hence  it  is  that  different  degrees  of  hardness  prevail  in 
nearly  every  razor  manufactured  ;  this  is  evidently  a  positive 
defect ;  and  so  long  as  it  continues  to  exist,  great  difference  of 
temper  must  exist  likewise.  Instead,  therefore,  of  hardening 
the  blade  from  the  anvil,  let  it  bo  passed  immediately  from  tho 
hands  of  the  forger  to  the  grinder  ;  a  slight  application  of  the 
stone  will  remove  the  whole  of  the  scale  or  coating,  and  the  razor 
will  then  be  properly  prepared  to  undergo  the  operation  of  hard- 
ening^ with  advantage.  It  is  plain  that  steel  in  this  state  heats  in 
the  'fire  with  greater  regularity,  and  that,  when  immersed,  be- 
comes equally  hard  from  one  extremity  to  the  other.  To  this 
may  be  added,  that,  as  the  lowest  possible  heat  at  which  steel 
becomes  hard  is  indubitably  the  best,  the  mode  here  recommend- 
ed will  be  found  the  only  one  by  which  the  process  of  hardening 
can  be  effected  with  a  less  portion  of  fire  than  is,  or  can  be,  re- 
quire I  in  any  other  way.  These  observations  are  decisive,  and 
will,  in  all  probability,  tend  to  establish  in  general  use  what  can- 
not but  be  regarded  as  a  very  important  improvement  in  the 
manufacturing  of  edge  steel  instruments. 

To  case-Jiarden  Snuill  Articles  of  Iron.— Fuse  to- 
gether, in  an  iron  vessel  or  crucible,  1  part  prussiate  of  potash 
and  10  parts  common  salt,  and  allow  the  article  to  remain  in  the 
liquid  3 )  minutes,  then  put  them  in  cold  water  and  they  will  be 
case-hardened. 


224  PRACTICAL   MECHANICAL   RECEIPTS. 

To  clean  (V  Sliof  Gnn.—^mp  clean  tow  around  the 
cleaning  rod  ;  then  take  a  bucket  of  tepid  water — soap-suds  if 
jn-ocurable— and  run  the  rod  up  and  down  the  barrel  briakly 
until  the  water  is  quite  black.  Change  the  water  until  it  runs 
quite  clear  through  the  nipple  ;  pour  clean  tepid  water  down  the 
barrel,  and  rub  dry  with  fresh  clean  tow  ;  run  a  little  sweet  oil 
on  tow  down  the  barrel  for  use.  To  clean  the  stock,  rub  it  with 
linseed  oil.  If  boiling  hot  water  is  used  the  barrel  will  dry 
sooner,  and  no  fear  need  be  apprehended  of  its  injuring  the  tem- 
per of  a  line  gun.  Some  sportsmen  use  boiling  vinegar,  but  we 
cannot  recommend  this  method.  The  reason  hot  water  does  not 
injurt!  the  gun,  is  that  boiling  water  is  only  21-2'  Fahr.,  aud  the 
gun  was  heated  to  -t-jO"  to  give  it  its  proper  temper. 

Grease  for  anoinfhu/  Gun-Barrels  on  tJie  Sea- 
Shore. — It  is  said  that  an  ointment  made  of  corrosive  sublimate 
and  lard  will  prove  an  effectual  protection  against  the  rusting  of 
gun-barrels  on  the  sea-shore. 

To  proteet  rollshed  3fetal  from.  llusf.—TaVe  10 
pounds  gutta-perrh?i,  20  pounds  mutton  suet,  ;.iO  pounds  beef 
suet,  2U  gaUons  m-ats'  foot  oil,  and  1  gallon  rape  oil.  Melt  to- 
gether until  thoroughly  dissolved  and  mixed,  and  color  with  a 
small  portion  of  rose  pink  :  oil  of  thyme  or  other  perfuming 
matter  may  be  added.  When  cold  the  composition  is  to  be  rub- 
bed on  the  surface  of  bright  steel,  iron,  brass,  or  other  metal, 
requiring  protection  from  rust. 

Neiv  Mode  of  removing  JJ*(..s^— Plunge  the  article  in  a 
bath  of  1  pint  hydrochloric  (muriatic)  acid  diluted  with  1  quart 
water.  Leave  it  there  24  hours  ;  then  take  it  out  and  rub  well 
with  a  scrubbing-brush.  The  oxide  will  come  off  like  dirt  under 
the  action  of  soaj).  Sliould  any  still  remain,  as  is  likely,  in  the 
corrod.-d  parts,  return  the  metal  to  the  bath  f  )r  a  few  hours 
more,  and  repeat  the  scrubbing.  The  me'.al  will  present  the 
appearance  of  dull  lead.  It  must  then  be  well  washed  in  plain 
water  several  times,  and  thoroughly  dried  betbro  a  tire.  Lastly, 
a  little  rubbing  with  oil  and  fine  emery  powder  will  restore  the 
polish.  Should  oil  or  grease  have  mingled  with  the  rust,  it  will 
bo  necessary  to  remove  it  by  a  hot  solution  of  soda  before  sub- 
mitting the  metal  to  the  acid.  This  last  attacks  the  rust  alone, 
withoul;  injuring  the  steel;  but  the  washing  in  i)liun  water  is 
all-important,  as,  after  the  jtroecss,  the  metal  will  absorb  oxygen 
from  the  atmosphero  freely  if  any  trace  of  the  acid  be  allowed  to 
remain. 

J*ifriJiration  of  Z/;»r.— Crranulato  zinc  by  melting,  and 
pouring  it,  while  vtuy  hot,  into  a  deep  vessel  lilh^d  with  water. 
iMace  lh(!  granulated  zinc  in  a  Hessian  crucible,  in  alternate  lay- 
•  crs,  with  one-fourth  its  weight  of  nitre,  with  an  excess  of  nitro  at 
the  top.  Cover  the  cruci;^l(^  and  secure  the  li  I ;  then  apply 
heat.  ^^'^leIl  dedagratlon  takes  place,  remove  from  the  fire,  H<;p- 
arato  the  dross,  and  run  the  zinc  into  an  ingot  mould.  It  iB 
quite  free  from  arsouic. 


PRACTICAL   MECHANICAL  RECEIPTS.  225 

To  remove  Must  from  Steel. — Rust  may  be  removed 
from  steel  by  immersing  the  article  in  kerosene  oil  for  a  few 
days.  The  rust  will  become  so  much  loosened  that  it  may  easily 
be  rubbed  off.  By  this  simple  method  badly  rusted  knives  and 
forks  may  be  made  to  present  a  tolerabla  appearance,  but  for 
new  goods  there  is  no  way  to  remove  rust  from  metal  but  by 
getting  below  it,  or  renewing  the  surface.  Where  it  is  not  deep- 
seated,  emery  paper  will  do,  but  if  long  standing  the  goods  must 
be  retinished. 

To  2)roteet  Polltihed  Steel  from  Must. — Nothing  is 
equal  to  pure  paraffine  for  preserving  the  polished  surface  of 
iron  and  steel  from  oxidation.  The  paraffine  should  be  warmed, 
rubbed  on,  and  then  wiped  off  with  a  woolen  rag.  It  will  not 
change  the  color,  whether  bright  or  blue,  and  will  i^rotect  the 
surface  better  than  any  varnish. 

Fiiie  Light  Yellow  Brass. — Melt  together  2  parts  copper 
and  1  part  zinc. 

Bright  Yelloiv  31allcable  Brass.— ^le\.i  together  7  parts 
copper  and  3  parts  zinc. 

Beep  Yellow  Malleable  Brass.— ^lelt  together  4  parts 
copper  and  i  part  zinc. 

Brass  inalleahle  whilst  hot. — Melt  together  3  parts 
copper  and  2  parts  zinc. 

Med  Brass. — Melt  together  5  parts  copper  and  1  j^art  zinc. 
As  much  as  10  parts  of  copper  to  1  part  of  zinc  may  be  used,  the 
color  being  a  deejjer  red  for  every  additional  part  of  copper' em- 
ployed. 

Brass  for  Buttons. — Copper  8  parts  and  zinc  5  parts. 
This  is  the  Birmingham  platin. 

Male  Brass  for  Buttons,  <£-c.  —Melt  together  16  parts 
fine  light  yellow  brass,  2  parts  zinc,  and  1  part  tin. 

Common  Male  Brass-— liilelt  together  25  parts  copper,  20 
parts  zinc,  3  parts  lead,  and  2  parts  tin. 

Fine  Male  Brass  for  Castings.— 'Melt  together  15  parts 
copper,  9  parts  zinc,  and  -1  parts  tin.     This  is  rather  brittle. 

Dark  Bra.<s  for  Castings.— ^le\t  together  90  parts  cop- 
per, 7  parts  zinc,  2  pp.rts  tin,  and  1  part  lead.  The  color  will  be 
still  deeper  by  iising  2  parts  less  of  zinc  and  1  part  more  each  of 
copi^cr  and  tin. 

Male  Brass  for  Gildiug.— Melt  togeihev  64  parts  copper, 
32  parts  zinc,  3  parts  lead,  and  i  part  tin. 

Med  Brass  for  Gilding.— Melt  together  82  parts  copper, 
18  parts  zinc,  3  parts  tin,  and  1  part  leacL 

Brass  for  Solder.— Melt  together  12  parts  fine  yellow  brass, 
6  parts  zinc,  and  1  part  tin.     Used  for  ordinary  brazing. 

10* 


226  PRACTICAL   MECHANICAL   RECEIPTS. 

Pale  lirass  for  Turning. — Melt  togetlier  98  parts  fin© 
brass  and  2  parts  lead. 

Med  Briiss  for  Turning. — Melt  together  G5  parts  copper, 
33  parts  zinc,  and  2  parts  lead. 

Ited  Brass  for  Wire. — Melt  together  72  parts  copper  and 
28  parts  zinc,  properly  annealed. 

l*ale  Urass  for  J/'/re.  — Melt  together  G4  parts  copper,  34 
parts  zinc,  and  2  parts  lead. 

To  ni<i1ie  Jirass  irhich  e.rpands  hi/  JLeat  equallg 
ivith'  Iron. — It  is  difficult  to  make  a  p(;nnancnt  joint  between 
brass  and  iron,  on  account  of  tli(>ir  nne(|Uiil  expansion  by  heat. 
In  a  recent  issue  of  tlie  journal  of  "  A2)pli('d  Chemistry,"  a  new 
alloy  is  given,  for  which  the  inventor  claims  an  expansion  by 
heat  so  nearly  similar  to  that  of  iron  as  to  allow  of  a  vmiou  be- 
tween them,  which,  for  all  jiractical  purposes,  is  permanent. 
This  consists  of  a  mixture  of  79  parts  copper,  15  parts  zinc,  and 
6  jiarts  tin. 

To  harden  Urass.— Bxaas  is  tempered  or  hardened  by  roll- 
ing or  hammering;  conseq\iently,  if  any  object  is  to  be  made  of 
tempered  brass,  the  hardening  must  be  done  before  working  it 
into  the  rc<]uired  shape. 

To  soften  lirass. — Heat  it  to  a  cherry  red,  and  plunge  it 
into  water. 

To  eorer  lirass  with  heautiful  Lustre  Colors.— 

Dissolve  1  ounce  cream  of  tartar  in  I  quart  of  boiling  water;  then 
add  .',  ounce  protochloride  of  tin  dissolved  in  4  ounces  cold  water. 
Next" heat  the  whole  to  boiling,  and  dec.int  the  clear  solution  from 
a  trilling  precipitate,  and  pour,  under  continual  stirring,  into  u 
solution  of  3  ounces  hyposulphate  of  so.la  in  \  pint  water,  then 
heat  again  to  boiling  ami  filter  from  the  separated  sulphur.  This 
s  ilution  i)ro<luc'\s  on  brass  the  various  lustre  colors,  depending 
on  the  I'ligth  of  time  during  which  the  articles  nro  allowed  to 
r.'inain  in  it.  The  colors  at  first  will  bo  liglit  to  dark  gold  yel- 
low, passing  through  all  t'.io  tints  of  red  to  an  iridescent  brown. 
A  similar  stories  of  colors  is  produced  by  suljjhido  of  copper  and 
lead,  which,  liowcvor.  are  not  remarkable  for  their  stability, 
whether  this  defect  will  be  obviated  by  the  use  of  the  tin  solu- 
tion, experience  and  time  alone  can  show. 

AlUtgs  of  I'latimnn-  and  Copper. — A  compound  of  1 
part  jilatiiMim  an  t  4  parts  co])per  is  of  a  yellow-pink  color,  hard, 
ductile,  i.iid  susceptible  nf  a  line  polish. 

An  alloy  of  3  parts  ])bitinum  and  2  parts  copper  is  nearly 
white,  very  hard,  and  brittle. 

Jied  Tonduir.  Put  into  n  cru<'ii>l(>  n.',  pounds  cojiper;  when 
fused  add  ^  pound  /ine;  these  m<'tais  will  combine,  forming  an 
alloy  of  a  reddish  color,  but  pos.sessing  more  lustre  than  copper, 
Bnd  also  great«:r  durability. 


PRACTICAL   MECHANICAL   RECEIPTS.  227 

IJlilte  Tombac. — "Wlien  copper  is  combined  with  arsenic, 
by  melting  them  together  in  a  close  crucible,  and  covering  the 
surliice  with  common  salt  to  prevent  oxidation,  a  white  brittle 
alloy  is  formed. 

French  Hell-J^Tetal. — The  metal  used  in  France  for  hand- 
bells, clock-bells,  etc  ,  is  made  of  £5  to  60  parts  copper,  3 J  to  40 
parts  tin,  and  10  to  15  parts  zinc. 

Alloy  of  Niclxel  and  Copper. — A  mixture  of  1  part  nickel 
and  2  parts  cojiper  produces  a  grayish-white  metal,  tenacious, 
ductile,  and  moderately  fusible. 

To  put  a  Black  Finish  on  Brass  Instruments. — 

Make  a  strong  solution  of  nitrate  of  silver  in  one  dish,  and  of 
nitrate  of  copper  in  another.  Mix  the  two  together,  and  plunge 
the  brass  in  it.  Now  heat  the  brass  evenly  till  the  required  de- 
gree of  dead  blackness  is  obtained.  This  is  the  method  of  pro- 
ducing the  beaiitiful  dead  black  so  much  admired  in  optical 
instruments,  and  which  was  so  long  kept  a  secret  by  the  French. 

Speculum  Metal  for  Telescopes.— Meli  7  pounds  of  cop- 
per, and  when  fused  add  3  pounds  zinc  an  1  4  j^ounds  tin.  These 
metals  will  combine  to  form  a  beautifv;l  alloy  of  great  lustre,  and 
of  a  light  5'ellow  color,  fitted  to  be  made  into  specula  for  tele- 
scopes. Mr.  Mudge  used  only  copper  and  grain  tin,  in  the  pro- 
portion of  2  pounds  of  the  former  to  14^-  ounces  of  the  latter. 

Phosphor  Bronzes. — A  great  advance  has  lately  been  made 
in  the  consti-ucti(in  of  bronTies,  by  the  addition  of  a  small  per- 
centage of  phosphorus,  although  the  precise  function  of  this 
substance  has  not  been  hitherto  well  understood.  According  to 
Levi  and  Kunzel,  however,  one  cause  of  the  inferiority  in  bronze 
consists  in  the  constant  presence  of  traces  of  tin  in  the  state  of 
an  oxide,  wliich  acts  mechanically  by  separating  the  molecules 
of  the  alloy,  thus  interposing  a  substance  which  in  itself  has  no 
tenacity.  The  addition  of  phosjahorus  reduces  this  oxide,  and 
renders  the  alloy  much  more  perfect,  imMroving  its  color,  its 
tenacity,  and  all  its  physical  properties.  The  grain  of  its  frac- 
ture resembles  more  that  of  steel,  its  elasticity  is  miich  augment- 
ed, and  its  resistance  to  pressure  sometimes  more  than  doubled. 
Its  durability  is  greater,  and  when  melted  it  is  of  greater  fluid- 
ity, and  fills  the  mould  in  its  finest  details. 

To  clean  Bronze. — It  was  observed  in  Berlin  that  those 
parts  of  a  bronze  statue  which  were  much  handled  by  the  public 
retained  a  good  surface,  and  this  led  to  the  conclusion  that  ftxt 
had  something  to  do  with  it.  An  experiment  was  therefore  tried 
for  some  years  with  four  bronzes.  One,  says  our  authority- 
Chambers'  Journal — was  coated  every  day  with  oil,  and  wiped 
"with  a  cloth  ;  another  Avas  washed  every  day  with  water  ;  the 
third  was  similarly  washed,  but  was  oiled  twice  a  year;  and  the 
foiirth  was  left  untoiached.  The  first  looked  beautifully;  the 
third,  which  had  been  oiled  twice  a  year,  was  passable;  the  sec- 
ond looked  dead;  and  the  fourth  was  dull  and  black. 


228 


PRACTICAL  MECHANICAL   RECEIPTS. 


Gongs  tind  Cf/mhals. — The  secret  metlunl  employed  by 
the  Chinese  for  working  the  hard  brittle  bronze  used  ibr  making 
gongs  and  cymbals,  seems  to  be  solved  by  the  fact  that  the  bronze 
of  which  these  instruments  are  made,  consisting  of  copper 
alloyed  with  about  2U  per  cent,  of  tin,  und  almost  as  brittle 
as  glass  at  orlinary  temperatures,  becomes  as  malleable  as  soft 
iron,  if  worked  at  a  tluU  red  heat.  This  discovery  was  recently 
made  in  Paris  by  MM.  Julien  and  Champion,  the  result  of  ex- 
periments at  the  Paris  Mint. 

F'onfoincinoi'Cdii's  Uronzes. — This  is  a  kind  of  bronze 
known  as  IVnitainemoroau's  bronze,  in  which  zinc  predominates. 
It  is  said  to  answer  well  for  chill  moulding,  that  is,  for  pouring 
in  metal  moulds,  by  which  method  it  is  rendennl  very  homoge- 
neous The  crystalline  nature  of  the  zinc  is  entirely  changed  by 
th<!  addition  of  a  small  proportion  of  coi)per,  iron,  etc.  The  alloy 
is  hard,  close-grained,  and  reseiubles  steel.  Moreover,  it  is  easier 
to  tile  than  eitlier  zinc  or  copper.  The  following  table  presents 
the  projjortions  in  use: 


Ziuc. 

Copper. 

Cast  Iron. 

Lead. 

90 

8 

1 

1 

91 

8 

0 

1 

92 

8 

0 

0 

92 

7 

1 

0 

97 

^ 

* 

0 

97 

3 

0' 

0 

99.} 

0 

^ 

0 

99 

1 

0 

0 

J7s<'  of  I'ltroliinn,  in  tiwnimj  ]\T('tnJs. — A  bronze  com- 
pos(!d  of  sevtai  parts  of  copper,  -1  of  zinc;,  an<l  1  of  tin,  has  been 
found  to  be  so  liard  as  to  be  dilHcult  to  work,  and  yet  of  consid- 
erable value  in  certain  ways  wlien  worked.  Various  methods 
have  been  attempted,  aiming  at  effecting  a  ready  working  of  this 
alloy,  and  M.  ]{echstein  has  recently,  by  soaking  the  alloy  in 
petroleum,  attained  this  desirable  eml. 

rj.r/Kinsion,  Jilcfal. — ^lelt  together  ',»  ])arts  of  lead,  2  parts 
of  antimony,  and  1  part  bismuth. 

Tiitenof/. — Melt  together  8  jiarts  of  copper,  5  parts  of  /auc, 
and  '.i  i)arts  of  nicikel. 

Woo<l\s  J*(ifenf  FnHibh'  IMiltil  melts  b<  tweeu  150"  and 
100'  Fahr.  It  ccmsists  of  '.\  ]>ar(s  <-a(lmium,  4  tin,  8  lend,  and  ];"» 
bismuth.  It  has  a  brilliant  metalli(r  lustre,  and  does  not  farnisli 
readily. 

yiu/ld  AJloif  ofSoflhnn  and  I'otosshnn. — If  4  ])arts 
Hodiuin  are  mixed  with  2.\  i>i>tassiuiii,  llie  alloy  will  have  exactly 
tlie  api)earanee  ami  consistency  of  mercury,  remaining  liquid  at 
tlio  ordinary  temperuturo  of  the  air. 


PRACTICAL  MECHANICAL   RECEIPTS.  'I'Z9 

Fusihle  Alloys. — Bismuth,  8  parts;  lead,  5  parts;  tin,  3 
parts;  melt  together.  Melts  below  iil2°  Fahr.  Or:  Bismuth,  2 
parts;  lead,  5  parts;  tin,  3  parts.  Melts  in  boiling  water.  Or: 
Lead,  3  parts;  tin,  2  parts;  bismuth,  5  parts;  mix.  Melts  at  197" 
Fahr.  The  above  are  used  to  make  toy-spoons,  to  surprise  chil- 
dren by  their  melting  in  hot  tea  or  coffee;  and  to  form  pencils 
for  writing  on  asses'  skin,  or  paper  prepared  by  rubbing  burnt 
hartshorn  into  it.  The  last  may  be  employed  as  an  anatomical 
injection,  by  adding  (after  removing  it  from  the  fire)  1  part  quick- 
silver (warm).     Liquid  at  172^  solid  at  140'^  Fahr. 

Engestvooni  Tufania.— Melt  together  4  parts  copper,  8 
parts  regulus  of  antimony,  and  1  part  bismuth.     When  added  to  . 
100  parts  of  tin,  this  compound  will  be  ready  for  use. 

TJte  most  Fusible  Alloij.— There  is  an  alloy  of  bismuth, 
tin,  and  lead,  which,  from  its  very  low  melting  point,  is  called 
fusible  metal.  Dr.  Von  Hauer  has  found,  however,  that  the  addi- 
tion of  cadmium  to  the  alloys  of  the  above-mentioned  metals  re- 
duces their  melting  point  still  lower.  An  alloy  of  4  volumes 
cadmium,  with  5  volumes  each  tin,  lead,  and  bismuth,  is  quite 
liquid  at  150"^  Fahr.  In  parts  by  weight,  the  above  would  be  22i 
parts  cadmium,  517.V  lead,  295  tin,  and  1050  bismuth.  An  alloy 
of  3  volumes  of  cadmium,  with  1  each  of  tin,  lead,  and  bismuth, 
fuses  at  153.}°  Fahr.,  and  an  alloy  of  1  equivalent  of  cadmium  with 
2  equivalents  each  of  these  three  other  metals,  at  155J°,  which  is 
also  the  fusing  point  of  an  alloy  of  1  part  each  of  all  the  four 
metals.  Dr.  Von  Ilauer  made  these  alloys  by  fusing  their  ingre- 
dients in  a  covered  porcelain  crucible  at  the  lowest  practicable 
temperature.  They  all  become  pasty  at  lower  temperatures  than 
those  given  above;  the  temperatures  quoted  are  those  at  which 
the  alloys  are  perfectly  fluid.  It  should  be  added  that,  unfor- 
tunately, all  these  alloys  very  rapidly  oxidize  when  placed  in 
water. 

Brass  Solder  for  hrazing  Iron  or  Steel.— ThiD.  plates 
of  brass  are  to  be  melted  between  the  pieces  that  are  to  be  joined. 
If  the  work  be  very  fine — as  when  two  leaves  of  a  broken  saw  are 
to  be  brazed  together-cover  it  with  pulvei'ized  borax,  dissolved 
in  water,  that  it  may  incorporate  with  some  brass  powder  which 
is  added  to  it;  the  piece  must  be  then  exposed  to  the  fire  with- 
out touching  the  coals,  and  heated  till  the  brass  is  seen  to  run. 

To  tin  Iron  for  Soldering,  <€r.— Drop  zinc  shavings  into 
muriatic  (hydrochloric)  acid,  until  it  will  dissolve  no  more;  then 
add  \  its  bulk  of  soft  water.  Iron,  however  rusty,  will  be  cleansed 
by  this  solution,  and  receive  from  it  a  sixfficient  coating  of  zinc 
for  solder  to  adhere  to. 

To  solder  ffrat/  Cast  Iron. — First  dip  the  castings  in  alco- 
hol, after  which,  sprinkle  muriate  of  ammonia  (sal-ammoniac) 
over  the  surface  to  be  soldered.  Then  hold  the  casting  over  a 
charcoal  fire  till  the  sal-ammoniac  begins  to  smoke,  then  dip  it 
into  melted  tin  (not  snider).  This  prepares  the  metal  for  solder- 
ing, which  can  then  be  done  in  the  ordinary  way. 


230  PRACTICAL   MECHANICAL   RECEIPTS. 

To  solder  Ferrules  for  Tool  II(i miles.— Hiike  the  fer- 
rule, l;ip  round  the  jointing'  a  small  piece  of  brass  wire,  then  just 
wet  the  ferrule,  scatter  ground  borax  on  the  joining,  put  it  on 
the  end  of  a  wire,  and  hold  it  in  the  fire  till  the  brass  fuses.  It 
■will  fill  up  the  joining,  and  form  a  perfect  solder.  It  may  after- 
ward be  turned  in  the  lathe. 

Solder  for  Iron. —Fuse  together  G7  parts  copper  and  33 
parts  zinc.     Or:  GO  parts  copper  and  i)  parts  zinc. 

Hard  Solder  for  Copper  or  Brass.— I&ke  13  parts 
co^jper  and  1  part  zinc.     Or:  7  copper,  3  zinc,  and  2  tin. 

Solder  for  Brass  iti  Gene r<tl.— Take  4  parts  of  scraps  of 
the  metal  to  be  soldered,  and  1  part  zinc. 

To  make  Solder-l>rop.>i.— Melt  the  solder  and  pour  it  in 
a  steady  stream  of  about  J  inch  in  diameter,  from  a  height  of  2 
or  3  inches,  into  cold  water;  taking  care  that  the  solder,  at  the 
time  of  pouring,  is  no  hotter  than  is  just  necessary  for  fluidity. 

Alum  in  il  m  Solder  — Mouray  employs  five  different  solders, 
being  different  proportions  of  zinc,  copper,  and  aluminum.  The 
copper  is  melted  first,  the  aluminum  is  then  added  in  3  or  4  por- 
tions ;  when  the  whole  is  melted,  it  is  stirred  with  an  iron  rod.  The 
crucible  is  then  withdrawn  from  the  fire,  the  zinc  gradually  stir- 
red into  the  mass,  and  tlie  whole  poured  into  ingot-shai)ed 
moulds,  previously  wii)ed  out  with  benzine.  The  parts  given  in 
the  following  proportions  are  by  weight. 

1. — 80  parts  zinc,  8  parts  copper,  12  jiarts  aluminum. 
2.-85     "         "      6     " 
3.-88     "         "      5     "  " 

4.  _90     "         "      4     "  " 

5.-94     "         "      2     "  " 

To  solder  Ala jni num. —The.  selection  of  either  of  the 
above  solders  depen<ls  upon  the  nature  of  the  object.  In  order 
to  qincken  its  fusion  on  the  metal,  a  mixture  of  3  parts  balsam  of 
copaiba  and  1  part  Venice  turpentine  is  made  use  of;  otlierwiso 
the  ojjeration  is  performcMl  in  exactly  the  sauio  manner  as  in  the 
brazing  of  otlier  metals.  Tlie  aluminum  sol.bT  is  s])read  without 
delay  on  tlnj  previously  licated  surfaces  to  be  fastened  together. 
hi  heating,  the  blue;  gas  flame  or  tli(>  turpentine  l)last  lamj)  is 
empli)yed.  The  more  and  oftener  the  solder  is  sjiread  over  tho 
surface,  tho  better  it  is. 

Aluminum  Sohhr.-M  soft  solder  is  fused  with  one-half, 
one-ti>uitli,  or  (nie-eighth  of  its  W(aglit  of  ziiu;  amalgam  (to  bo 
made  by  dissolving  zinc  in  juereury),  a  more  or  less  hard  and 
easily  fusilde  solder  is  obtained,  wliich  7iiay  lie  used  to  solder 
nluniinum  to  itself  or  to  other  metals. 

Wcldinij  (JinniKt^Hion.—VvLHQ  borax  M'ith  1-16  its  weight  of 
Bal-aniinoniac;  cool,  ])ulverizo,  and  mix  with  an  e(|ual  w<>iglit  of 
(piiekliiue,  wlien  it  is  to  l)o  Kprinkle<l  on  the  red-hot  iron  and  tho 
latter  r-'placed  in  tho  fire. 


9     " 

(i 

7     " 

<< 

6     " 

(< 

4     " 

K 

selection 

of  either 

PRACTICAL   MECHANICAL  EECEIi'TB.  231 

WeUliiifj  Powder  for  Iron  and  Steel. — For  w^ekliDg  iron 
and  steel  a  composition  has  lately  been  patented  in  Belgium, 
consisting  of  iron  lilings,  40  parts;  borax,  2U  parts;  balsam  of 
copaiba,  or  some  other  resinous  oil,  2,  and  sal-ammoniac,  3  parts. 
They  are  mixed,  heated,  and  i^ulverized.  The  process  of  welding 
is  much  the  same  as  usual.  The  surfaces  to  be  welded  are  pow- 
dered with  the  composition,  and  then  brought  to  a  cherry-red 
heat,  at  which  the  powder  melts,  when  the  portions  to  be  united 
are  taken  from  the  fire  and  joined.  If  the  pieces  to  be  welded 
are  too  large  to  be  both  introduced  at  the  same  time  into  the 
forge,  one  can  be  first  heated  with  the  welding  powder  to  a  cher- 
ry-red heat,  and  the  others  afterward  to  a  white  heat,  after  which 
the  welding  may  be  eflfected. 

Tf'elding  Composifionfor  C(tst  Steel. — Take  borax,  10 
parts;  sal-ammoniac,  1  part;  grind  or  pound  them  roughly  to- 
gether, then  fuse  them  in  a  metal  pot  over  a  clear  fire,  taking 
care  to  contini:e  the  heat  until  all  spume  has  disappeared  from 
the  surface.  When  tlie  li<|uid  appears  clear,  the  composition  is 
ready  to  be  poured  out  to  cool  and  concrete;  afterward,  being 
ground  to  a  fine  powder,  it  is  ready  for  use.  To  use  this  compo- 
sition, the  steel  to  be  weldo  1  is  first  raised  to  a  bright  yellow 
heat,  it  is  then  dipped  among  the  welding  powder,  and  again 
placed  in  the  fire  until  it  attains  the  same  degree  of  heat  as  be- 
fore; it  is  then  ready  to  be  i^laced  under  the  hammer. 

IVeldiiiff  Powder. — For  iron  or  steel,  or  both  together,  ca'- 
cine  and  pulverize  together  100  parts  iron  or  steel  filings,  10  sal- 
ammoniac,  6  borax,  5  balsam  of  copaiba.  One  of  the  pieces  is  to 
be  heated  red,  careful!}'  c'eaned  of  scale,  the  composition  is  to  be 
spread  upon  it,  and  the  other  piece  applied  at  a  white  heat  and 
welded  with  the  hammer. 

Welding  Composition. — Take  15  parts  borax,  2  of  sal- 
ammoniac,  and  2  of  prussiate  of  potash.  Being  dissolved  in 
water,  the  water  should  be  gradually  evaporated  at  a  low  tem- 
jjcrature. 

IVelding  Composition. — Mix  10  parts  borax  with  1  i3art 
sal-ammoniac;  fuse  the  mixture,  and  pour  it  on  an  iron  plate. 
When  cold,  pulverize  it,  and  mix  it  Avith  an  cqiial  weight  of  quick- 
lime, sprinkle  it  on  iron  heated  to  redness,  and  replace  it  in  the 
fire.     It  may  be  welded  below  the  usual  heat. 

Compound  for  ii'eJdhiff  Steel. — The  following  composi- 
tion is  said  to  be  siiiierior  to  borax  for  welding  steel.  Mix  coarsely 
powdered  borax  with  a  thin  paste  of  Prussian  blue;  then  let  it 
dry. 

Amalgam  of  Gold  for  gilding  Brass,  Copper,  tCe. — 

Place  one  part  grain  or  leaf  gold  in  a  small  iron  saucepan  or  ladle, 
perfectly  clean,  then  add  8  parts  mercury,  and  apply  a  gentle 
boat,  when  the  gold  will  dissolve;  agitate  the  mixture  for  one 
minute  with  a  smoot'i  iron  stirrer,  and  poi^r  it  out  on  a  clean 
plate  or  stone  slab.     When  cold  it  is  reatly  for  use. 


232  PRACTICAL   MECHANICAL   RECEIPTS. 

Fluxes  for  Soldering  and  Welding  — 

For  Iron  or  steel Borax  or  sal-ammoniac. 

"    Tinned  iron Resin  or  chloride  of  zinc. 

"    Copper  and  brass Sal-ammoniac  or  chloride  of  zinc. 

"    Zinc Chloride  oi  zinc. 

«'    Lea  1 Tallow  or  resin. 

"    Lead  and  tin  \  ipes llesin  and  sweet  oil. 

To  f/ild  with  Gold  Anialgani.  For  gilding  brass,  cop- 
per, itc.  The  metal  to  be  gilded  is  tir.^t  rabbed  over  with  a  solu- 
tion of  nitrate  of  mercury,  and  then  covered  with  a  very  thin  lilm 
of  the  amalgam.  On  heat  being  applied,  the  mercury  volatilizes, 
leaving  the  gold  behind.  A  much  less  proportion  of  gold  is  often 
employed  than  the  above,  where  a  very  thin  and  cheap  gilding 
is  required,  as,  by  increasing  the  quantity  of  the  mercury,  the 
precious  metal  may  be  extended  over  a  much  larger  surface. 

Jfoiv  to  fasten  Ruhher  to  Wood  and  Metal.- As  rub- 
ber plates  and  rings  are  now-a-days  almost  (exclusively  used  for 
making  connections  between  steam  and  other  pipes  and  appara- 
tus, much  annoyance  is  often  experienced  by  the  impossibility 
or  imperfectness  of  an  air-tight  connection.  This  is  obviated 
entirely  by  employing  a  cement  which  fastens  equdly  wellto 
the  rubber  and  to  the  metal  or  wood.  Such  cement  is  prepared 
by  a  solution  of  shellac  in  ammonia  This  is  best  made  by 
soaking  pulverized  gum-shellac  in  ten  times  its  weight  of  strong 
ammonia,  M'hcn  a  slimy  mass  is  oljtained,  which,  in  three  to  four 
weeks,  will  become  liquid  without  the  iise  of  hot  water.  This 
softens  the  rubber,  and  becomes,  after  volatilization  of  the  am- 
monia, hard  and  impermeable  to  gases  aid  fluids. 

Marine  Cement  for  uniting  Leatlier  to  Gutta- 
percha.— This  will  unite  leather  to  gutta-percha,  and  is  imper- 
vious to  damp.  It  is  made  by  dissolving  by  the  aid  of  heat,  1 
part  india-rubber  in  nai)litha,  and  when  melted  adding  2  parts 
shellac,  and  melting  until  mixed.  Pour  it  while  hot  on  metal 
plates  to  cool.  When  required  for  use,  melt,  and  apj)lv  with  a 
brush.  This  cement  does  not  adhere  very  well  to  vulcanized 
rubber,  and  the  joint  is  always  weak. 

Cement  to  unite  India- liHldn'r.—Tiiko  16  parts  gutta- 
percha, 4:  j)arts  india-rublxT,  2  i)arts  common  calker's  pitch,  1 
part  linseed  oil.  Tlio  ingredients  are  nudted  together,  and  used 
hot.     It  will  unite  leather  or  rubber  that  has  not  been  vulcanized. 

Gutta-rerelta  Cement  for  Leather  /;r/f.s.  Dissolve 
a  (|uaiitity  (if  gutta-percha  in  clilorofurm  in  (piantity  to  make  n 
fluid  of  honey-like  consistence.  When  spread  it  will  dry  in  a 
few  moments".  Heat  tlie  surfaces  at  a  fin?  or  gas  Hame  until 
softened,  and  apply  th''m  together.  Small  patches  of  leather  ctm 
be  thus  cemented  on  boots,  etc.,  so  as  almost  to  defy  detection, 
and  some  shoemakers  employ  it  with  great  siu-ness  for  this  i)Ur- 
poHo.  It  is  wat<!rprof)f,  and  will  answer  almost  anywhere  unless 
exposed  to  heat,  which  softens  it, 


PEACTICAL    MECHANICAL   RECEIPTS.  233 

Antimonoid.—A.  welding  powder,  nuniLd  antimonoid,  has 
been  in  use  for  some  time  past  in  Germany,  and  found  to  be  of 
great  efficiency.  The  formula  for  its  preparation  has,  until  lately, 
been  kept  a  secret;  it  consists  of  i  parts  iron  turnings,  3  parts 
borax,  2  parts  borate  of  iron,  and  1  of  water. 

CaouU'hour  Ccnienf  is  made  as  follows:— Gutta-percha, 
3  jjarts ;  virgin  india-rubber  (caoutchouc),  1  part  (both  cut 
small ;  ;  pyrogenoiis  oil  of  turpentine,  or  bisulphuret  of  carbon, 
8  pf.rts  ;  mix  in  a  close  vessel,  and  dissolve  by  the  heat  of  hot 
water.     This  cement  should  be  gently  heated  before  being  used. 

Cement   fnv    attaehinff    Metal    Letters  to   Plate 

Glass. — Cojjal  varnish,  16  parts;  drying  oil,  6  parts;  turpentine 
and  oil  of  turpentine,  of  each  3  parts;  liquefied  glue  (made  with 
the  least  possible  rpiantity  of  water\  5  jiarts.  Melt  together  in 
a  water-bath,  and  add  fresh  slacked  lime  (i^erfectly  dry  and  in 
very  fine  powder),  10  parts. 

Cement  for  Metal  and  Glass. — Mix  2  ounces  of  a  thick 
solution  of  glue  with  1  ounce  of  linseed  oil  varnish,  or  f  ounce 
Venice  turpentine  ;  boil  them  together,  stirring  them  until  they 
mix  as  thoroughly  as  possible.  The  pieces  cemented  should  be 
tied  together  for  2  or  3  days.  This  cement  will  firmly  attach  any 
metallic  siibstance  to  glass  or  porcelain. 

To  f/iiard  against  LK'ru.'itation  in  Boilers. — Prof. 
Chandler  recommends  the  following  precautions:  The  use  of  the 
purest  waters  that  can  be  obtained,  rain-water  wherever  possi- 
ble. Fre(|uent  use  of  the  blow-off  cock.  That  the  boilers  never 
be  emptied  while  there  is  fire  enough  to  harden  the  deposit. 
Frequent  washing  out.  Experiments  on  the  efficacy  of  zinc, 
lime-water,  carbonate  of  soda,  carbonate  of  baryta,  chloride  of 
ammonium,  some  substance  containing  tannic  acid,  linseed  meal, 
and  the  electro-magnetic  indiictor. 

Management  of  the  Witter  to  prevent  Boiler  In- 
■crustation. — Blowing  off.  The  frequent  blowing  off  of  small 
quantities  of  water,  say  a  few  gallons  at  a  time,  is  undoubtedly 
cae  of  the  most  efiective  and  simple  methods  for  removing  sedi- 
ments and  preventing  their  hardening  on  the  sides  of  the  boiler. 
The  water  entering  the  boiler  should  be  directed  in  such  a  way 
as  to  sweep  the  loose  particles  toward  the  blow-off  cocks,  that 
when  these  are  open  they  may  be  carried  out  with  the  water. 
This  blowing  off  should  take  place  at  least  two  or  three  times 
daily,  perhaps  much  oftener. 

To  preserve  Timherfrom  Beeay  and  Dr;/- Hot.— The 

best  way  to  preserve  timber  exposed  to  the  action  of  the  weather 
is  to  force  into  the  pores  of  well-seasoned  wood  as  much  carbolic 
acid  or  creosote  as  possible.  This  soon  resinifies,  and  most  effec- 
tually preserves  the  timber  from  dry-rot  and  decay.  On  a  large 
scale,  as  for  railway  sleepers,  expensive  ajipliances  are  needed; 
but  for  barns  or  outbuildings  it  may  be  api^lied  to  considerable 
advantage  by  the  use  of  a  paint  brush. 


234  PRACTICAL   MECHANICAL   RECEIPTS. 

To  fasten  Chamois  ami  other  Leather  to  Iron  and 

Steel.— Dr.  Carl  AV.  Heinischen,  of  Dresden,  gives  the  following 
receipt  for  the  above  purpose:  Spread  over  the  metal  a  thin,  hot 
solution  of  good  glue  ;  soak  the  leather  with  a  warna  solution  of 
gall-nuts  before  placing  on  the  metal,  and  leave  to  dry  under  an 
even  pressure.  If  fastened  in  this  manner  it  is  impossible  to 
separate  the  leather  from  the  metal  without  tearing  it. 

Incrustation  in  Boilers.— The  only  effectual  remedy  is  to 
blow  out  frequently.  Blow  out  once  a  week  at  least  10  per  cent, 
of  the  water  in  tlie  boilers.  It  should  be  done  while  the  water  is 
at  rest,  that  is,  before  starting  in  the  feed  water.  A  practical 
engineer  says:  Our  boilers  were  badly  incrusted.  We  loosened 
the  scale  with  chisels  and  kerosene  oil,  and  after  running  them 
a  year  as  above,  they  came  out  as  clean  and  bright  as  could  be. 

Scale  in  Boilers —A  jiractical  engineer  recommends  the 
following:  Get  some  cow  or  ox  feet,  just  as  they  are  cut  off  in  the 
slaughter-house,  put  them  in  a  wire  net  fine  enough  to  detain  the 
small  bones  from  getting  from  the  T)oiler  into  tlie  blow-off  pipe. 
Use  5  of  the  feet  to  a  G  liorse-jiower  boiler,  and  no  further  trouble 
with  scale  in  the  boilers  will  be  experienced.  They  must  I'e  re- 
placed every  two  or  three  months,  according  to  the  quality  of 
the  water.     They  do  not  make  the  water  foam. 

Solution  to  preserve  TFoof^.— With  every  25  gallons  of 
water  required,  mix  5  pounds  chloride  of  zinc.  Wood  steeped 
in  this  solution  will  effectually  resist  dry-rot. 

ToJ^i/auize  1  rood  or  Corda f/e.—JmmorsG  the  wood  or 
cordage  in  a  solution  of  50  or  iV)  inivta  wat(>r  and  1  part  corrosive 
sublimate.  This  preserves  it  from  decay,  and  renders  wood  tou"h 
and  more  difficult  to  split.  ° 

Tojtreserre  and  harden  f food.— 'Wood  steeped  in  a  so- 
lution of  copjieras  becomes  harder  and  more  indestructible. 

German  lleceipt  f<tr  coatintj  IFood  with  a  Sub-. 
8f<inrc  as  liurd  as  ,S'/o;»r.  Melt  togetlier  40  parts  chalk,  iO 
resin,  and  4  linseed  oil;  to  tins  should  be  addivl  1  part  oxide  of 
copper,  and  afterward  1  ])art  sulpliuric  acid.  This  last  ingredi- 
ent must  be  added  carefully.  The  mixture,  while  hot,  is  ai)i)Iied 
with  a  brush,  and  forms,  when  dry,  a  varnish  as  hard  as  stone. 
This  is  an  excellent  ai)])licati(m  to  ))rotect  ])osts,  tubs,  or  other 
wooden  articles  which  are  set  in  the  eai'th. 

To  prereut  the  Sjtlittinff  of  Lo<js  and  I'lauhs.-  Lr>gH 
and  ])lanks  split  at  fh(^  ends  bcejiusr  tlic  (■xi)osi(l  surface  dries 
fiLstcr  than  tlie  insirle.  Saturate  muriatic,  acid  witli  Jim,.,  and 
a])ply  like  whitewasli  to  the  ends.  The  (^Idoride  of  cah-ium  form- 
e<l  attriu^ts  moisture  from  the  air  and  i)revents  the  splitting. 
Tobacconists'  signs,  and  other  wooden  images,  have  usuallv  a 
liolo  bored  through  tlieir  centre,  from  top  to  l)ottom;  this  in  a 
f;reat  measure  jirevents  tlie  outer  surface  from  cracking,  by  al- 
1  >wing  the  wood  to  dry  and  shrink  more  uniformly. 


PRACTICAL   MECHANICAL   RECEIPTS.  235 

To  petrify  Wooden  Objects.— Take  equal  quantities  of 
gem-salt,  rock-alum,  white  vinegar,  chalk,  and  pebbles,  powdered. 
Mix  all  these  ingredients;  ebullition  will  ensue.  After  it  has 
ceased,  throw  some  wooden  objects  into  this  liquid,  and  let  them 
soak  for  4  or  5  days,  at  the  end  of  which  time  they  will  be  trans- 
formed into  petrifactions. 

To  preserve  Wood  under  Water.— V^'oo A  impregnated 
with  creosote  oil  has  been  found  to  resist  effectually  the  ravages 
of  the  teredo  worm;  this  worm  being  the  cause  of  decay  by  honey- 
combing the  entire  substance  of  the  wood.  In  G  ermany  chloride 
of  zinc  is  used  for  this  purpose,  the  timber  being  placed  in  boil- 
ers, partly  exhausted  of  air,  and  the  vapor  of  chlorine  thus 
driven  into  it.  These  remedies  are  recommended  by  a  commit- 
tee of  practical  experts,  appointed  by  the  Academy  of  Sciences 
in  Holland,  to  ascertain  the  best  means  for  preserving  timber 
under  water. 

Preservation  of  TFoorf.— Armand  Muller  has  instituted 
some  interesting  experiments  on  this  siibject,  and  arrives  at  the 
conclusion  that  the  phosphate  of  baryta,  formed  by  the  mutual 
decomposition  of  phosphate  of  soda  and  chloride  of  barium,  in 
the  pores  of  the  wood,  is  one  of  the  best  preservative  agents  avail- 
able to  chemists.  Soak  the  wood  5  days  in  a  7  per  cent,  solution 
of  phosphate  of  soda,  and,  after  drying,  suspend  in  a  13  per  cent, 
solution  of  chloride  of  barium  for  7  days.  It  is  believed  that 
/wood  thus  prepared  will  withstand  the  action  of  moisture  better 
than  with  any  other  preparation.  The  chief  obstacle  to  the  use 
*of  such  chemicals  is  in  their  cost. 

To  coat  Copper  Plates  with  Brass.— 'E.^vose  the 
plates,  heated  sufdciently,  to  the  fumes  of  zinc.  Zinc  boils  and 
is  vaporized  by  heating  it  to  a  white  heat. 

To  coat  the  Inside  of  Copper  Vessels  with  Brass. 
—Dissolve  1  part  zinc  amalgam  in  2  parts  muriatic  acid  ;  add  1 
part  argol  (crude  tartar),  and  add  sufficient  water  to  fill  the  ves- 
sel ;  then  boil  it  in  the  vessel. 

« 

Graeger's  Process  for  covering  Iron  atul  Steel 
tvitli  Copper  without  a  Battery.— Ihe  objects  are  first 
well  cleaned,  and  then  painted  over  with  a  sohition  of  proto- 
chloride  of  tin,  and  immediately  afterward  with  an  ammoniacal 
solution  of  sulphate  of  copper.  The  layer  of  copper  thus  pro- 
duced adheres  so  firmly  to  the  iron  or  steel,  that  the  different 
objects  can  be  rubbed  and  polished  with  fine  chalk  without  in- 
juring the  deposit.  The  tin  solution  is  prepared  with  1  part 
crystallized  chloride  of  tin,  2  parts  water,  and  2  parts  hydro- 
chloric acid.  The  copper  solution,  with  1  part  sulphate  of  cop- 
l^er,  IG  parts  water,  adding  ammonia  sufficient  to  redissolve  the 
precipitate  first  thrown  down  by  it.  Zinc  and  galvanized  iron 
can  be  treated,  according  to  Bocttger,  directly  by  the  copper 
soliation,  without  using  the  tin  salt.  The  above  process  may  be 
found  useful  by  gilders,  and  for  various  ornamental  purposes. 


238  PRACTICAL   MECHANICAL   RECEIPTS. 

To  deposit  Copper  upon  Cast  Iron.— The  pieces  of 
cast  iron  are  first  placed  in  a  bath  male  of  50  parts  hytlro- 
cliloric  acid,  Ri)ecific  gravit}'  1.105,  and  1  part  nitric  acid  ;  next, 
in  a  second  batli,  composed  of  10  parts  nitric  acid,  10  parts  of 
chloride  of  copper,  dissolved  in  80  parts  of  the  same  hydro- 
chloric acid  as  just  alhided  to.  The  objects  are  rnbbed  with  a 
woolen  rag  and  a  soft  brush,  next  washed  with  water,  and  again 
immersed  iiiitil  the  desired  thickness  of  copper  is  dcjiosited. 
When  it  is  desired  to  give  the  a^jpearance  of  bronze,  the  copper 
surface  is  rubbed  with  a  mixture  of  4  parts  sal-ammoniac  and  1 
part  each  oxalic  and  acetic  acids  dissolved  in  30  parts  water. 

IFeil's  I*rocess  for  coating  Iron   icifh  Copper. — 

This  process  yields  a  coating  of  copper  of  great  brightness  and 
strong  cohesion.  The  object,  whether  of  cast  or  wrought  iron, 
is  freed  from  rust  by  immersion  for  from  5  to  10  minutes  in 
water  containing  2  per  cent,  of  muriatic  acid,  and  subsequent 
scrubbing  for  \  hour  with  a  wire  brusli  and  sand,  then  washin'^ 
in  water  until  all  traces  of  acid  are  removed.  It  is  then  covered 
with  zinc  wire  in  spiral  turns  of  about  6  inches  from  each  other, 
which  also  s.Tves  as  a  means  of  suspension.  The  bath  consists 
of  a  solution  of  8  parts  caustic  soda  in  1  0  parts  water,  of  which 
11  quarts  are  mixed  with  50  ounces  Eoclielle  salts  and  1  J.\  ounces 
sulphate  of  copper,  making  a  liquid  of  a  density  eipial  to  19° 
Baiime.  It  retains  its  activity  as  long  as  the  copper  is  kept  re- 
placed, and  deposition  from  it  i)roceeds  with  great  regularity. 
'Ihe  material  of  the  vessel  is  best  when  made  of  wood,  lined  with 
gutta-percha,  and  covered  with  a  wooden  lid.  When  the  coating 
is  of  sulHcieut  thickness,  the  object  is  removed  from  the  bath, 
first  washed  with  water  sliglitly  acidifird  with  sulpliuric  acid, 
and  then  witli  i)ure  water  until  the  disappearance  of  all  traces 
of  acid ;  after  this  it  passes  into  a  drying-room  heated  to  132° 
Fahr.  The  bronzing,  when  required,  is  obtained  by  a  bath  of 
sulphide  of  sodium,  or  by  means  of  the  same  bath  as  above, 
somewhat  modified,  tliat  is,  by  increasing  the  proi)orti(m  of  cop- 
l)er  to  a  threefold,  in  which  case  the  bath  no  longer  deposits 
coi)j)er,  but,  to  all  appearances,  bronze.  l?y  reducing  the  points 
of  contact  between  the  iron  and  wire,  though  retaining  tlio 
spiral  turns  at  uniform  distances,  the  deposit  gradually  assumes 
a  number  of  colors  in  the  following  series,  viz.:  orange,  silver- 
white,  pale  yellow,  golden  yellow,  carmine,  green,  brown,  and 
dark  bronze.  As  soon  as  the  desired  color  is  attaine  1,  the  object 
is  washe  1  in  warm  water,  and  again  dried  at  132  '.  Between  each 
subsequent  change  of  color  is  an  interval  of  about  5  minutes. 
The  reaction  is  more  decided  when  the  alkaline  reaction  of  fho 
bath  is  stronger.  For  indoor  work  or  ornaments  the  time  of  im- 
mersion may  vary  from  3  to  72  hours  ;  for  outdoor  objects  a 
mueii  longer  time  would  Ije  necessary. 

To  tin  a  Cojtpcr  I'cssel. — Boil  the  copper  vessel  with  a 
solution  of  stannat<;  of  polassa  mixed  with  tin  borings,  or  Ixiil 
witli  tin  tilings  .iml  caustic  alkali  or  cream  of  tartar.  In  a  few 
minules  a  layer  of  pure  tin  v.ill  bo  firmly  attached. 


PRACTICAL   MECHANICAL   RECEIPTS.  237 

To  tin  Iron  Pots  and  other  Domestic  Articles. — 

The  articles  are  cleaned  with  sand,  and.  if  necessary,  with  acid, 
and  put  then  in  a  bath,  prepared  with  1  ounce  cream  of  tartar, 
i  ounce  tin  salt  (protochloride  of  tin),  10  quarts  water.  This 
bath  must  be  kept  at  a  temperature  of  190'^  Fahr  ,  in  a  stone- 
ware or  wooden  tank.  Bits  of  metallic  zinc  are  put  into  and 
between  the  different  pieces.  When  the  coat  of  tin  is  considered 
thick  enough,  the  articles  are  taken  out  of  the  fluid,  washed  with 
water,  and  dried. 

To  till  hy  the  Moist  Way. — Make  a  solution  of  1  part 
protochloride  of  tin  in  10  parts  water,  to  which  add  a  solution 
of  2  parts  of  caustic  soda  in  20  j^arts  water ;  the  mixture  bo- 
comes  turbid,  but  this  does  not  affect  the  tinning  operation, 
which  is  effected  by  heating  the  objects  to  be  tinned  in  this 
fluid,  care  being  taken,  at  the  same  time,  to  place  in  the  liquid 
a  piece  of  perforated  block  tin  plate,  and  to  stir  up  the  fluid 
during  the  tinning  with  a  rod  of  zinc. 

To  tin  Iron  without  the  Aid  of  Heat— 'lo  105  quarts 
water  are  added  6|  pounds  rye  meal ;  this  mixture  is  boiled  for 
30  minutes,  and  next  filtered  through  cloth  ;  to  the  clear  but 
thickish  liquid  are  added  2  !3  pounds  pyrophosphate  of  soda, 
37J  pounds  protochloride  of  tin  in  crystals  (so-called  tin  salt), 
147^  poiinds  neutral  i^rotochloride  of  tin,  3.V  to  4  ounces  sul- 
phuric acid  ;  this  li(|uid  is  placed  in  well-made  wooden  troiighs, 
and  serves  more  especially  for  the  tinning  of  iron  and  steel  wire 
(previously  polished)  for  the  use  of  carding  machines.  When, 
instead  of  the  two  salts  of  tin  just  named,  cyanide  of  silver  and 
cyanide  of  potassium  are  taken,  the  iron  is  perfectly  silvered. 

To  cleanse  Iron  for  Tinninr/. — The  metal  must  be 
cleansed  by  immersion  in  an  acid  solution  ;  for  new  metal,  this 
solution  should  be  sulphuric  acid  and  water,  but  for  old  metal, 
muriatic  acid  and  water  ;  next  scour  with  sand,  and  cleanse  well 
with  water. 

To  tin  Iron. — First  cleanse  as  above,  then  heat  the  article 
just  hot  enough  to  melt  the  tin,  rub  the  surface  over  with  a 
piece  of  sal-ammoniac,  and  sprinkle  some  of  the  sal-ammoniac 
m  powder  over  it ;  then  apply  the  tin  and  wipe  it  over  evenly 
with  a  piece  of  tow. 

Cold  Tinning. — Eub  pure  tinfoil  and  quicksilver  together 
until  the  amalgam  becomes  soft  and  fusible,  clean  the  surface  to 
be  tinned  with  spirits  of  salt  (hydrochloric  acid),  and,  while 
moist,  rub  the  amalgam  on,  and  then  evaporate  the  quicksilver 
by  heat. 

To  tin  Cast  Copper  or  .Brass.— Make  a  saturated  solu- 
tion of  oxide  of  tin  (tin  putty),  in  potash  lye;  add  to  the  solution 
some  tin  filings  or  shavings;  make  it  as  hot  as  possible ;  then 
introduce  the  brass  or  copper  and  it  will  bo  tinned  in  a  few 
seconds. 


238  PRACTICAL   MECHANICAL   RECEIPTS. 

Sfolhd'y.  tnctUod  of  thiiihuj  Copper,  Brass,  and 
Iron  hi  the  Coltf,  and  irifhonf  Apparatus.  The  ob- 
ject to  be  coated  with  tin  must  be  entirely  free  tVoni  oxide  or 
rust.  It  must  be  carefully  cleaned,  and  cave  b(^  taken  that  no 
prease  spots  are  left ;  it  makes  no  ditferenee  whethi>r  the  object 
be  cleaned  mechanically  or  chemically.  Two  ])roparations  are 
requisite  for  the  purpose  of  tinning  Zinc  powder — the  best  is 
that  prepared  artificially  by  melting  zinc  and  ])ouring  it  into  an 
iron  mortar.  It  can  be  (iasily  pulverized  immediately  after  solidi- 
fication ;  it  should  be  about  as  fine  as  writing  sand.  A  solution 
of  protochloride  of  tin,  containing  5  to  10  per  ci'nt.,  to  which  as 
much  pulverized  cream  of  tartar  must  be  added  as  will  go  on  the 
jioint  of  a  knife. 

The  object  to  be  tinned  is  moistened  with  the  tin  solution, 
after  winch  it  is  rubbed  hard  with  the  zinc  powder.  The  tinning 
appears  at  once.  The  tin  salt  is  decomposed  by  the  zinc,  metal- 
lic tin  being  deposited.  When  the  object  tinned  is  polished 
brass  or  copper,  it  appears  as  beautiful  as  if  silvcireil,  and  retains 
its  lustre  for  a  long  time.  This  mrthod  may  be  used  in  a  labora- 
tory to  preserve  iron,  steel,  and  copper  api)aratus  from  rust ;  and 
would  become  of  great  importance  if  the  tinning  could  be  made 
as  thick  as  in  the  dry  way,  but  this  has  not  as  yet  been  accom- 
plished. 

To  tin  Copper  Tiiltes. — W.  WoUweber  i-ccommends  for 
Ktill-worras  cojjper  tubes  tinned  inside  in  tlie  following  manner  : 
To  a  solution  of  Rochdle  salts  a  solution  of  salts  of  tin  is  added; 
a  prociijitate  of  stannous  tartrate  is  Ibrmed,  whicli  is  washed  and 
then  dissolv(!d  in  caustic  lye.  The  co])per  tube,  which  has  first 
been  rinsed  with  sulphuric  acid  and  then  washed,  is  then  filled 
with  the  alkaline  solution,  warmed  a  little,  and  touched  with  a 
tin  rod,  which  causes  the  deposition  of  a  coat  of  metallic  tin. 

T >  tin  a  tr!>rn.  Copper  Kettle.  —A  thick  coating  may  be 
obtained  by  preparing  a  tinning  solution  of  zinc  dissolved  in 
muriatic  acid,  making  the  solution  as  thick  or  heavily  charged 
witli  zinc  as  possil)le,  adding  a  litth;  sal-ammoniac.  Ch'an  the 
inside  f)f  the  Jci'ttle,  place  it  in  a  charcoal  fir(!  until  a  ])iece  of 
blncdc  tin  placed  inside;  melts,  then  rub  the  melted  tin,  with  some 
of  the  tinning  solution,  (juickly  on  tlui  c<ii)iier  surface,  by  means 
of  ft  ball  of  oakum  and  a  little  powdered  resin  ;  the  tin  will 
readily  adhere.  Wrought  iron  and  steel  may  be  tinned  in  the 
sauK;  maniur. 

I'^lne  (ireen  Jironze.  Dissolve  2  ounces  verdigris  and  1 
ounce  Kftl-ammoniac  in  1  ])int  vinegar,  and  dilute  the  mixture 
with  watiT  until  it  tastes  l.ut  slightly  metallic,  when  it  must  bo 
boiled  for  a  few  minutes,  and  liltcred  for  use.  Cojiper  nuMlals, 
Ac,  previously  thoroughly  cleaned  fron  grease  ami  dirt,  are  to 
be  Hteej)ed  in  the  liqiior  at  the  boiling  point,  until  the  desired 
e(T(!ct  is  jjroduccd.  Care  must  be  taken  not  to  kce|)  them  in  tlie 
solution  too  long.  Wlmn  taken  out,  tli<'y  should  be  carcCiilly 
Wiwhed  in  hot  water,  uiid  well  dried.  GivoH  an  antique  appear- 
ance. 


PRACTICAL   MECHANICAL   RECEIPTS.  239 

To  galvanize  Iron. — The  difference  between  galvanized 
plates,  so-called,  and  "sheet-tin,"  is,  that  the  latter  is  sheet-iron 
covered  with  a  thin  coating  of  block-tin,  while  the  former  is 
sheet-iron  covered  with  a  thin  coating  of  zinc.  To  effect  the  lat- 
ter result,  the  iron  plates  are  first  immersed  in  a  cleansing  bath 
of  equal  parts  of  suli^huric  or  muriatic  acid  and  water,  used 
warm.  They  are  then  scrubbed  with  emery  or  sand,  to  clean 
them  thoroughly  and  detach  all  scales,  if  any  are  left ;  after 
which  they  are  immersed  in  a  preparing  bath  of  equal  parts  of 
saturateil  solutions  of  chloride  of  zinc  and  chloride  of  ammonium, 
from  which  bath  they  are  directly  transferred  to  the  fluid  metallic 
bath,  consisting  of  20  chemical  equivalents  of  zinc  to  1  of  mer- 
cury ;  or,  by  weight,  6i0  pounds  of  zinc  to  106  of  mercury,  to 
which  are  added  from  5  to  6  pounds  of  sodium.  As  soon  as  the 
iron  has  attained  the  temperature  of  this  hot  fluid  bath,  which  is 
only  680°  Fahr  ,  it  may  be  removed,  and  will  then  be  found 
thoroughly  coated  with  zinc.  Care  must  be  taken  not  to  leave 
the  plates  too  long  immersed  in  this  bath,  as  its  afiinity  for  iron 
is  such  that  they  may  become  dissolved.  This  is  the  case  with 
thin  plates  of  wrought-iron,  which,  even  when  \  inch  thick,  may 
be  dissolved  in  a  few  seconds.  It  is  safe,  therefore,  to  let  the 
bath  previouslj'  act  on  some  wrought  iron,  so  that  it  dissolves  a 
portion  of  it,  in  order  to  satisfy  its  inconveniently  great  aflBnity 
for  this  metal. 

Green   Bronzes  for    FU/ures    and    Busts.— Green 

bronzes  require  a  little  more  time  than  those  already  described. 
They  depend  upon  the  formation  of  an  acetate,  carbonate,  or 
other  green  salt  of  copper  upon  the  surface  of  the  metal.  Steep- 
ing for  some  days  in  a  strong  solution  of  common  salt  will  give 
a  partial  bronzing  which  is  very  beautiful,  and,  if  washed  in 
water  and  allowed  to  dry  slowly,  is  very  permanent.  Sal-ammo- 
niac may  be  substituted  for  common  salt.  Even  a  strong  solu- 
tion of  sugar  alone,  or  with  a  little  acetic  or  oxalic  acid,  will 
produce  a  green  bronze  ;  so  also  will  exposure  to  the  fumes  of 
dilute  acetic  acid,  to  weak  fumes  of  hydrochloric  acid,  and  to 
several  other  vapors.  A  dilute  solution  of  ammonia  allowed  to 
dry  upon  the  cojjper  surface  will  leave  a  green  tint,  but  not  very 
permanent. 

To  bronze  Brass  Orange,  Greenish  Gray,  and 
Violet  Tint. — An  orange  tint,  inclining  to  gold,  is  j^roduced 
by  first  polishing  the  bl-ass,  and  then  plunging  it  for  a  few 
seconds  into  a  neutral  solution  of  crystallized  acetate  of  copper, 
care  being  taken  that  the  solution  is  completelj^  destitute  of  all 
free  acid,  and  possesses  a  warm  tempei'ature.  Dipped  into  a 
bath  of  copper,  the  resulting  tint  is  a  grayish  green,  while  a 
beautiful  violet  is  obtained  by  immersing  it  for  a  single  instant 
in  a  solution  of  chloride  of  antimony,  and  rubbing  it  with  a 
Btick  covered  with  cotton.  The  temperature  of  the  brass  at  the 
time  the  operation  is  in  progress  has  a  great  influence  upon  the 
beauty  and  delicacy  of  the  tint;  in  the  last  instance  it  should  be 
heated  to  a  degree  so  as  just  to  be  tolerable  to  the  touch. 


240  PRACTICAL   MECHANICAL   RECEIPTS. 

Uronzlug  trifJi  liJeachincf  Poivdev.— 'Electrotypes  may 
be  Vjronzed  green,  having  the  api)eiirance  of  ancient  bronze,  by 
a  very  simple  process.  Take  a  small  portion  of  bleaching  pow- 
der (chloride  of  lime\  place  it  in  the  bottom  of  a  dry  vessel, 
and  suspend  the  medal  over  it,  and  cover  the  vessel;  in  a  short 
time  the  medal  will  ac(inire  a  green  coating,  the  depth  of  which 
may  be  regulated  by  the  quantity  of  bleaching  powder  use  1,  or 
the*  time  that  the  medal  is  suspended  in  its  fumes  ;  of  course, 
any  sort  of  vessel,  or  any  means  by  which  the  electrotype  may  be 
exposed  to  the  fumes  of  the  powder,  will  answer  the  purpose  ;  a 
few  grains  of  the  powder  is  all  that  is  required.  According  as 
the  medal  is  clean  or  tarnished,  dry  or  wet,  when  suspended, 
different  tints,  with  different  degrees  of  adhesion,  will  be  ob- 
tained. 

JMolre  Jii'onze. — A  moire  appearance,  vastly  siiperior  to 
that  usually  seen,  is  produced  by  boiling  the  object  in  a  solution 
of  sulphate  of  copper.  According  to  tlie  proportions  observed 
between  the  zinc  and  the  coi)per  in  the  composition  of  the  brass 
article,  so  will  the  tints  obtained  vai'y-  In  many  instances  it 
requires  the  empli>yment  of  a  slight  degree  of  friction  with  a 
resinous  or  v.axy  varnish,  to  bring  out  the  wavy  appearance 
characteristic  of  moire,  which  is  also  singularly  enhanced  by 
dropping  a  few  iron  nails  into  the  bath. 

French  lii'<mze. — An  eminent  Parisian  scnlptor  makes  use 
of  a  mixture  of  i  ounce  sal-ammoniac,  J  ounce  common  salt,  1 
ounce  spirits  of  hartshorn,  and  1  imperial  quart  of  vinegar.  A 
gf)od  result  will  also  be  obtained  by  substituting  an  additional  \ 
ounce  sal-ammoniac,  instead  of  the  spirits  of  hartshorn.  The 
piece  of  metal,  being  well  cleaned,  is  to  Vx;  rubbiul  with  one  of 
these  solutions  and  then  dried  by  friction  with  a  clean  brush. 
If  the  hue  be  found  too  pale  at  the  end  of  2  or  3  days,  the  opera- 
tion may  be  repeated.  It  is  found  to  be  more  advantageous  to 
operate  in  the  sunshine  than  in  the  shade. 

To  hfoiize  Cop/ier  iritli  Sulpliiir. — When  objects  made 
of  c(ipp<?r  are  immerseil  in  lueUrd  sulphur  mixed  with  himp- 
l)laek,  the  objects  so  treated  obtain  the  ajjpearance  of  bronze, 
and  can  be  polished  without  losing  that  aspect. 

Anti'liK'  lii'inizc.  Dissolve  1  ounce  sal-ammoniac,  3 
ounces  cream  of  tartar,  and  (J  oun(;es  common  salt,  in  1  i>int  liot 
water  ;  then  add  2  ounces  nitrate  of  copper,  dissolved  in  i  pint 
water;  mix  well,  ami  apjdy  it  rcjieatedly  to  the  article,  ]ilac.'d 
in  a  damp  situation,  by  jucans  of  a  brush  moistened  therewith. 
This  produces  a  very  anti<jue  effect. 

lirtnizintf    l.it/uitls  for    Tin    <7ff.vf/»< (/.<».     Wash  Ihrni 

over,   all  IT    lirillg    Well    clcallr  I    Hlld     wipi'd.    wit  ll  a  Sol  111  i.  ill  i  if    I 

]>art  sulphate  of  iron,  and  1  jtart  siiljiliate  of  (;()])|)(r,  in  2  '  ])arls 
watt-r  ;  afterward  with  a  solution  of  1  jtarts  verdigris  in  11  of 
distilled  vinegar;  leave  for  an  hour  to  dry,  and  then  polish  with 
a  soft  brush  and  crocus. 


PRACTICAL   MECHANICAL   RECEIPTS.  241 

To  bronze  Iron  Castings.— Iron  castings  may  be  bronz- 
ed by  thorough  cleaning  and  subsequent  immersion  in  a  solu- 
tion of  sulphate  of  cojiper,  when  they  acquire  a  coat  of  the  latter 
metal.     They  must  be  then  washed  in  water. 

Surface  Bronzing.— This  term  is  applied  to  the  proces? 
of  impiuiing  to  the  surfaces  of  figures  of  wood,  plaster  of  Paris, 
&c.,  a  metallic  appearauce.  This  is  done  by  first  giving  them  a 
coat  of  oil  or  size  varnish,  and  when  this  is  nearly  dry,  apjilying 
with  a  dabber  of  cottoa  or  a  camel-hair  pencil,  any  of  the  metallic 
bronze  powders  ;  or  the  powder  may  be  placed  in  a  little  bag  of 
musliu,  and  dusted  over  the  surface,  and  afterward  finished  off 
with  a  wad  of  linen.     The  surface  must  be  afterward  varnished. 

Beautiful  lied  Bronze  Powder.— ^li^  together  sul- 
phate of  copper,  100  ^larts  ;  carbonate  of  soda,  GO  parts  ;  apply 
heat  until  they  unite  into  a  mass,  then  cool,  powder,  and  a'l'd 
copper  filings,  15  parts;  well  mix,  and  keep  them  at  a  white  heat 
for  20  minutes,  then  cool,  powder,  wash  thoroughly  with  water, 
and  di-y. 

Gold-Colored  Bronze  J*o«YZ^r.— Verdigris,  Bounces; 
tutty  powder,  4  ounces;  borax  and  nitre,  each  2  ounces;  bichlo- 
ride of  mercury,  \  ounce  ;  make  them  into  a  paste  with  oil,  and 
fuse  them  together.  Used  in  japanning  as  a  gold  color.  Or: 
grind  Dutch  foil  or  i^ure  gold  leaf  to  an  impalpable  powder. 

Bright  Yelloiv  Dye  for  TFoort.— To  every  gallon  of  water 
necessary  to  cover  the  veneers,  add  1  pound  French  berries  ; 
boil  the  veneers  till  the  color  has  penetrated  through;  add  some 
brightening  liquid  (see  next  receipt)  to  the  infusion  of  the 
French  berries,  and  let  the  veneers  remain  for  2  or  3  hours,  and 
the  color  will  be  very  bright. 

Liquid  forlfriffhteninff  and  setting  Colors.— To  e^erj 

pint  of  strong  aquafortis,  add  1  ounce  grain  tin,  and  a  piece  of 
sal-ammoniac  the  size  of  a  walnut;  set  it  by  to  dissolve,  shake 
the  bottle  round  with  the  cork  out,  from  time  to  time:  in  the 
course  of  2  or  3  days  it  will  be  fit  for  use.  This  will  be  found  an 
admirable  liquid  to  add  to  any  color,  as  it  not  only  brightens  it, 
but  renders  it  less  likely  to  fade  from  exposure  to  the  air. 

Fine  Blue  Bye  for  Wood.— Into  a  clean  glass  bottle  put 
1  pound  oil  of  vitriol,  and  4  ounces  best  indigo  pounded  in  a 
mortar  (take  care  to  set  the  bottle  in  a  basin  or  earthen  glazed 
pan,  as  it  will  effervesce*, put  the  veneers  into  a  copper  or  stone 
trough  ;  fill  it  rather  more  than  -J  with  water,  and  add  as  much 
of  the  vitriol  and  indigo  (stirring  it  about)  as  will  make  a  fine 
blue,  which  you  may  know  by  trying  it  with  a  jjiece  of  white 
paper  or  wood  ;  let  the  veneers  remain  till  the  dye  has  struck 
through.  The  color  will  be  much  improved  if  the  solution  of 
indigo  in  vitriol  be  kept  a  few  weeks  before  using  it.  The  color 
will  also  strike  better  if  the  veneers  be  boiled  in  plain  water  till 
completely  soaked  through,  and  left  for  a  few  hours  to  dry  par- 
tially, previous  to  immersing  them  in  the  dye. 

11 


242  PRACTICAL  MECHANICAL   nnCKIPTS. 

Uriffht  Green  Dye  for  Wood.— Proceed  as  in  either  of 
the  previous  receiijts  to  procUace  a  yellmv;  Lut  instead  of  adding 
aquafortis  or  the  brightening  liquid,  add  as  much  vitriolated  in- 
digo as  will  produce  the  desired  color. 

Jiriffht  lied  Dye  for  Wood. — To  2  pounds  genuine  Brazil 
dust  add  4  gallons  water;  put  in  as  many  veneers  as  the  liquor 
•will  cover  ;  boil  them  for  3  hours,  then  add  2  ounces  alum  and 
2  ounces  aquafortis,  and  keep  it  lukewarm  until  it  has  struck 
through. 

lied  Dye  for  Wood. — To  every  pound  of  logwood  chips 
add  'A  gallons  of  water;  put  in  the  veneers,  and  boil  as  in  the  last; 
then  add  a  sufficient  quantity  of  the  brightening  liquid,  tiU  the 
color  is  of  a  satisfactory  tint;  heep  the  whole  as  warm  as  you  can 
bear  your  finger  in  it,  till  the  color  has  sufficiently  penetrated. 
The  logwood  chips  should  be  picked  from  all  foreign  substances 
with  which  it  generally  abounds,  as  bark,  dirt,  A:c. ;  and  it  is 
always  best  when  fresh  cut,  which  may  be  known  by  its  appear- 
ing of  a  bright  red  color;  for  if  stale,  it  will  look  brown,  and  not 
yield  so  much  coloring  matter. 

Jtose-eolored  Dye  for  If'ood. — Monier  produces  a  fine 
pink  or  rose-color  on  wood  of  cellulose,  especially  that  of  the 
ivory  nut,  by  immersing  it  first  in  a  solution  of  iodide  of  potas- 
sium, 1}  ounces  jier  pint  of  water,  in  which  it  remains  for  sevi-ral 
hours,  when  it  is  placed  in  a  bath  of  corrosive  sublimate,  135 
grains  to  the  pint.  When  properly  dyed  it  is  washed  and  var- 
nished over.  We  should  think  that  less  poisonous  materials 
might  be  found  to  answer  the  same  purpose. 

Drif/ht  Purjde  Dye  for  Wood. — Boil  2  pounds  logwood, 
either  in  chips  or  powder,  in  4  gallons  water,  with  the  veneers; 
after  boiling  till  the  color  is  well  struck  in,  add  by  degrees  vit- 
riolated indigo  till  the  purple  is  of  the  shade  reijuircd,  whitdi 
may  be  known  by  trying  it  with  a  piece  of  jiaper;  let  it  then  boil 
for  1  hour,  and  keeji  the  licjuid  in  a  milk-warm  state  till  the 
color  has  penetrated  the  veneer.  This  method,  when  properly 
managed.  Mill  produce  a  brilliant  purple. 

Yellow  Jlnisa,  for  Turning. — (Common  article.") — Copper, 
20  lbs. ;  zinc,  10  lbs. ;  lead,  from  1  to  5  ozs.  Put  in  the  iLoud  last 
before  pouring  off. 

Jfrf?  J?i7/s.s,  FOBTuRNiNa. — Copper,  24  Ibs. ;  zinc,  5  lbs. ;  lead, 
8  o/.s.     But  in  the  lead  last  before  i)ouring  off. 

Jted  Jiross,  for  Tuknino. — Copper,  1(!0  lbs.;  zinc,  50  Ib.s. ; 
lead,  10  lbs. ;  antimony,  '14  oz.s. 

Atntther  ISrfi.Hs,  for  Turning. — Copper,  32  lbs.  zinc,  10  lbs; 
lead,  1  lb. 

Jiesf.  lieil  Jii'ti.ss,  i-ou  Kink  Castings. — Copjier,  24  lbs.; 
zinc,  5  lbs. ;  bismuth,  1  oz.  Put  in  the  bismutti  last  before  pour- 
ing off. 


PKACTICAL   MECHANICAL   RECEIPTS.  243 

Bronze  Metal. — Copper,  7  lbs. ;  zinc,  3  lbs. ;  tin,  2  lbs. 

Or:  Copper,  1  lb.;  zinc,  12  lbs.;  tin,  8  lbs. 

JSell  3Tefal,  for  laege  Bells. — Copper,  100  lbs.;  tin,  from 
20  to  25  lbs. 

Hell  3£efctl,  fob  shall  Bells. — Copper,  3  lbs;  tin,  1  lb. 

Cock  3Ietal. — Copper,  20  lbs.;  lead,  8  lbs.;  litharge,  1  oz, ; 
antimony,  3  ozs. 

Hardening  for  Britannia. — (To  be  mixed  separately 
from  the  other  ingredients. ) — Copper,  2  lbs. ;  tin,  1  lb. 

Britannia  Metal,  1st  Quality. — Tin,  150  lbs. ;  copper,  3 
lbs. ;  antimony,  10  lbs. 

2d  Quality. — Tin,  140  lbs. ;  copper,  3  lbs. ;  antimony,  9  lbs. 

Fob  Casting. — Tin,  210  lbs. ;  copper,  4  lbs. ;  antimony,  12  lbs. 

Foe  SpiK>rtXG.  — Tin,  100  lbs. ;  Britannia  hardening,  4  lbs. ; 
antimony,  4  lbs. 

Fob  Registers. — Tin,  100  lbs.;  hardening,  8  lbs.;  antimony, 
8  lbs. 

Foe  Spouts. — Tin,  140  lbs.;  copper,  3  lbs.;  antimony,  6  lbs. 

Fob  Spoons. — Tin,  100  lbs. ;  hardening,  5  lbs. ;  antimony,  10 
lbs. 

Fob  Handles.  — Tin,  140  lbs. ;  copper,  2  lbs. ;  antimony,  5  lbs. 

Foe  Lamps,  Pillabs,  and  Spouts. — Tin,  300  lbs. ;  copper,  4 
lbs. ;  antimony,  15  lbs. 

Casting. — Tin,  100  lbs.;  hardening,  5  lbs.;  antimony,  5  lbs. 

lAning  MetaJ,  fob  Boxes  of  Railboad  Cabs. — Mix  tin,  24 
lbs. ;  copper,  4  lbs. ;  antimonv,  8  lbs.  (for  a  hardening) ;  then  add 
tin,  72  lbs. 

Fine  Silver-colored  Metal. — Tin,  100  lbs. ;  antimony,  8 
lbs. ;  copper,  4  lbs. ;  bismuth,  1  lb. 

German  Silver,  1st  Qualitt  fob  Casting. — Copper,  50  lbs, ; 
zinc,  25  lbs. ;  nickel,  25  lbs. 

2d  Quality  fob  Casting. — Copper,  50   lbs.;   zinc,   20  lbs.; 
nickel  (best  pulverized;,  10  lbs. 

Foe  Rolling.— Copper,  60  lbs.;  zinc,  20  lbs. ;  nickel,  25  lbs. 

Fob  Bells  and  othee  Castings. —Copper,  60  lbs.;  zinc,  20 

lbs. ;  nickel,  20  lbs. ;  lead,  3  lbs. ;   iron  (that  of  tin-plate 

being  best),  2  lbs. 

Imitation  of  Silver. — Tin,  3  ozs.;  copper,  4  lbs. 

Hard  White  ^fetal.— Sheet  brass,  32  ozs.;  lead,  2  ozs.; 
tin,  2  ozs. ;  zinc,  1  oz. 

Tombac.— Copper,  16  lbs.:  tin,  1  lb.;  zinc,  1  lb. 

Jted  Tombac.— Co-pper,  10  Ib.s. ;  zinc,  1  lb. 


244  PRACTICAL   MECHANICAL    RECEIPTS. 

PincJibecJc.  — Copper,  5  lbs. ;  zinc,  1  lb. 

Metal  for  taking  Inijft'^ssions.—Ije&d,  3  lbs.;  tin,  2  lbs.; 
bismuth,  5  lbs. 

SpanisliTiitania. — Iron  or  steel,  8  ozs. ;  antimony,  IGozs. ; 
nitre,  3  ozs.  Melt  and  harden  8  ozs.  tin  with  1  oz.  of  the  above 
compound. 

Another  Tutania. — Antimony,  4  ozs.;  arsenic,  1  oz.,  tin, 
2  lbs. 

Gun-3Ietal. — Bristol  brass,  112  lbs. ;  zinc,  14  lbs. ;  tin,  7  lbs. 

liivet  Metal. — Copper,  32  ozs. ;  tin,  2  ozs. ;  zinc,  1  oz. 

Rivet  Metal,  fob  Hose. — Copper,  64  lb.s.;  tin,  1  lb. 

Fasihle  Allan  (which  melts  in  boiling  water). — Bismuth,  8 
ozs. ;  tin,  3  ozs. ;  lead,  5  ozs. 

Fusible  Alloy,  foe  silveking  Glass. — Tin,  6  ozs.;  lead,  10 
ozs. ;  bismuth,  21  ozs. ;  mercury,  a  small  quantity. 

Solder,  for  Gold. — Gold,  6  pwts. ;  Silver,  1  pwt. ;  copper,  2 
pwts. 

Solder,  for  Silver. — (For  the  use  of  jewellers.) — Fine  silver, 
19  pwts. ;  copper,  1  pwt. ;  sheet  brass,  10  pwts. 

White  Solder,  for  Silver. — Silver,  1  oz. ;  tin,  1  oz. 

White  Solder,  for  R.used  Britanni.v  Ware.— Tin,  100  lbs.; 
copper,  3  ozs. ;  to  iiiukc  it  free,  add  lead,  3  ozs. 

Jiest  Soft  Solder,  for  Cast  BritanniaWake  —  Tin,  8  lbs.; 
lead,  5  lbs. 

YelloiV  Solder,  for  Br^vss  or  Copper. — Copper,  1  lb. ;  zinc, 
1  lb. 

Soft  Cement,  for  Steam-Boilers,  Ste.am-Pipes,  Ac— Red  or 
white  lead,  iu  oil,  4  parts;  iron  borings,  2  to  3  parts. 

J  ford  Cement. — Iron  borings  and  salt  water,  and  a  small 
quantity  of  sal-ammoniac  with  fresh  water. 

Stat iia rij  ]iron::e. — Dareet  has  discovered  that  this  is  com- 
po.s('d  of  copper,  01. 1;  zinc,  5.");  load,  1.7;  tin,  1.4. 

Bronze  for  Cannon  of  large  CVrftftrc— Copper,  90; 
tin,  7. 

Bronze  for  Cannon  of  small  Calibre.— Goiiprr,  03: 
tin,  7. 

Bronze  for  Medals. — Copper,  100;  tin,  8. 

Altoff  for  <'i/mbals.~Coi)i>cr,  80;  tin,  20; 

Metal  for   tin'  Mirrors  of  Jie/leefing  Teleseopes.^ 

Copper,  K.iJ;  tin,  DO, 


PRACTICAL  MECHANICAL   RECEIPTS.  245 

White  uLrge}Uan  — Copper,  8;  nickel,  3;  zinc,  35.  This 
beautiful  composition  is  in  imitation  of  silver. 

Chinese  Silver. — M.  Mairer  discovered  the  following  pro- 
portions :  Silver,  2.5;  copper,  65.24;  zinc,  19.52;  nickel,  13; 
cobalt  of  iron,  0.12. 

Tatciuig. — Copper,  8;  nickel,  3;  zinc,  5. 

Printing  Churacters. — Lead,  4;  antimony,  1.  For  stereo- 
type plates — Lead,  9 ;  antimony,  2 ;  bismuth,  2. 

Orange  Dye  for  Wood. — Let  the  veneers  be  dyed  by 
either  of  the  methods  given  for  a  fine  deep  yellow,  and  while 
they  are  still  wet  and  saturated  with  the  dye,  transfer  them  to 
the  bright  red  dye,  till  the  color  penetrates  equally  throughout. 

Silver-Grag  Dge  for  Wood. — Expose  any  quantity  of 
old  iron,  or,  what  is  better,  the  borings  of  gun-barrels,  &c.,  in 
any  convenient  vessel,  and  from  time  to  time  sprinlde  them  with 
muriatic  acid,  diluted  in  1  times  its  quantity  of  water,  till  they 
are  very  thickly  covered  with  rust;  then  to  every  6  pounds  add 
1  gallon  of  water  in  which  has  been  dissolved  2  ounces  salt  of 
tartar  (carbonate  of  potassa);  lay  the  veneers  in  the  copper,  and 
cover  them  with  this  liquid  ;  let  it  boil  2  or  3  hours  till  well 
soaked,  then  to  every  gallon  of  liquor  add  \  pound  of  green 
copi^eras,  and  keep  the  whole  at  a  moderate  temperature  till  the 
dye  has  sufiiciently  penetrated. 

To  dye  Veneers.  —Some  manufacturers  of  Germany,  who 
had  been  supplied  from  Paris  with  veneers,  colored  throughout 
their  mass,  were  necessitated  by  the  late  war  to  produce  them 
themselves.  Mr.  Puscher  states  that  experiments  in  this  direc- 
tion gave  in -the  beginning  colors  fixed  only  on  the  outside, 
while  the  inside  was  untouched,  until  the  veneers  were  soaked 
for  24  hours  in  a  solution  of  caustic  soda  containing  10  per  cent. 
of  soda,  and  boiled  therein  for  \  hour;  after  washing  them  with 
sufficient  water  to  remove  the  alkali,  they  may  be  dyed  through- 
out their  mass.  This  treatment  with  soda  eflfects  a  general  dis- 
integration of  the  wood,  whereby  it  becomes,  in  the  moist  state, 
elastic  and  leather-like,  and  ready  to  absorb  the  color;  it  must 
then,  after  dj'eing,  be  dried  between  sheets  of  paper  and  subject- 
ed to  pressure  to  retain  its  shape. 

To  dye  Fcweer.s  ^?«cfc.— Veneers  treated  as  in  last  receipt 
and  left  for  24  hours  in  a  hot  decoction  of  logwood  (1  part  log- 
wood to  3  water),  removing  them  after  the  lapse  of  that  time,  and, 
after  drying  them  superficially,  putting  them  into  a  hot  sohition 
of  copperas  (1  part  copperas  to  30  water),  will,  after  24  hours, 
become  beautifully  and  completely  dyed  black. 

To  stain  Wood  like  Ebony. — Take  a  solution  of  sulphate 
of  iron  (green  cojiperas),  and  wash  the  wood  over  with  it  2  or  3 
times;  let  it  dry,  and  apply  2  or  3  coats  of  a  strong  hot  decoction 
of  logwood;  wipe  the  wood,  when  dry,  with  a  sponge  and  water, 
and  polish  with  linseed  oil. 


246  PRACTICAL   MECHANICAL   RECEIPTS. 

To  dye  Veneers  Yellow. — A  solution  of  1  part  picric  acid 
in  GO  water,  with  the  addition  of  so  much  ammonia  as  to  become 
jjerceptible  to  the  smell,  dyes  veneers  yellow,  which  color  is  not 
in  the  least  affected  by  subsequent  varnishing. 

To  dye  Yeneern  Hose- Color. — Coralline  dissolved  in  hot 
water,  to  which  a  little  caustic  soda  and  one-fifth  of  its  volume 
of  soluble  glass  has  been  added,  proiuces  rose-colors  of  different 
shades,  dependent  on  the  amount  of  coralline  taken. 

To  dye  Veneers  Silver-Gray.— The  only  color  which 
veneers  will  take  up,  without  previous  treatment  of  soda,  is 
silver-gray,  produced  by  soaking  them  for  a  day  in  a  solution  of 
1  part  copperas  to  100  parts  water. 

Black  Stain  for  Immediate  Use.— 'Boil  J  pound  chip 
logwood  in  '.i  quarts  water,  add  1  ounce  pearlash,  and  apply  it 
hot  to  the  work  with  a  brush.  Then  takei  poiand  logwood,  boil 
it  as  before  in  2  quarts  water,  and  add  I  ounce  verdigris  and  J 
ounce  green  copperas  ;  strain  it  off,  put  in  \  i)ound  rusty  steel 
filings;  with  this,  go  over  the  work  a  second  time. 

To.'itain  Wood  li (/Jit  Mahogany  <7o/or.— Brush  over 
the  surlixco  with  dihitt;d  nitrous  acid,  and  when  dry  ai)ply  the 
following,  with  a  soft  ])rush  :  dragon's  blood,  4  ounces  ;  com- 
mon soda,  1  ounce  ;  spirits  of  wine,  3  pints.  Let  it  stand  in 
a  warm  place,  shake  it  frequently,  and  then  strain.  Repeat  the 
application  until  the  proper  color  is  obtained. 

To  stain  Dark  Mahotjauy  Color.— Boil  l  pound  mad- 
der and  2  ounces  logwood  in  1  gallon  water  ;  then  brush  the 
wood  well  over  with  the  hot  licpiid.  When  dry,  go  over  the 
whole  with  a  solution  of  2  drams  pearlash  in  1  quart  of  water. 

Jieeehirood  Mah oga ny.  —Dissolve 2 ounces  dragon's  blood 
and  1  oiance  aloes  in  1  (piart  rectified  spirit  of  wine,  and  apply 
it  to  the  surface  of  the  wood  i)reviously  well  polished.  Or:  Wjxsli 
over  the  surface  of  the  wood  with  atjuafortis,  and  when  thorough- 
ly dry  give  it  a  coat  of  the  above  varnish.  Or:  Boil  1  jiound  log- 
wood chips  in  2  (]uarts  water,  and  add  2  haudfuls  of  walnut  \^Q^'\\ 
boil  again,  then  strain,  and  add  1  pint  good  vinegar:  apjily  a.s 
above. 

A  rti/ieial  3Iahoyany.— The  following  method  of  giving 
any  species  of  wood  of  a  elosi^  grain  tlie  apjx'aranco  of  mahogany 
in  texture,  density,  and  polish,  is  said  to  be  practised  in  Franco 
with  success.  The  surface  is  ]>laned  smooth,  and  the  wood  is 
tlien  rubbed  witli  a  solution  of  nitrous  acid;  1  ounce  dragon's 
l)lood  is  dissolved  in  nearly  a  ])int  of  spirits  of  wine;  this,  and  ^ 
ounce  carbonate  of  soila,  are  tlien  to  Ixs  inixe(l  together  and  fil- 
ttTiid,  and  the  li(iuid  in  tliis  thin  state  is  to  be  laid  on  with  a  soft 
brush.  This  jmxjess  is  to  bo  repeated,  uiid  in  a  short  inttirval 
afterward  the  wool  1  jiossesses  the  external  aii]iearance  of  mahogany. 
When  llio  ]tf)lisli  diminishes  in  brilliancy,  it  may  bo  restored  by 
the  use  of  a  little  cold-drawn  linseed  oil. 


PRACTICAL   MECHANICAL   RECEIPTS.  247 

To  stain  Mahogantf  Color.— Vnre  Socotrine  aloes,  1 
ounce;  dragon's  bloo^l,  Jounce;  rectified  spirit,  1  pint;  dissolve, 
and  apply  2  or  3  coats  to  tbe  surface  of  the  wood;  finish  off  with 
■wax  or  oil  tinged  with  alkanet.  Or  :  Wash  over  the  wood  with 
strong  aquafortis,  and  when  dry,  apply  a  coat  of  the  above  var- 
nish; polish  as  last.  Or:  Logwood,  2  ounces;  madder  8  ounces; 
fustic,  1  ounce;  water,  1  gallon;  boil  2  hours,  and  apply  it 
several  times  to  the  wood  boiling  hot;  when  dry,  slightly  brush 
it  over  with  a  solution  of  pearlash,  1  ounce,  in  water,  1  quart; 
dry  and  polish  as  before.  Or:  Logwood,  1  part;  water,  8  parts. 
Make  a  decoction  and  apply  it  to  the  wood;  when  dry,  give  it  2 
or  3  coats  of  the  following  varnish:  dragon's  blood,  1  part;  spirits 
of  wine,  20  parts.     Mix. 

Fine  Black  Stain.— BoW  1  pound  logwood  in  4  quarts 
water,  add  a  double  handful  of  walnut-peel  or  shells;  boil  it  up 
again,  take  out  the  chips,  add  1  pint  best  vinegar,  and  it  will  be 
fit  for  use  ;  apply  it  boiling  hot.  This  will  be  improved  by  ap- 
l^lying  a  hot  solution  of  green  copperas  dissolved  in  water  (an 
ounce  to  a  qi;art),  over  the  first  stain. 

To  unit  ate  Hosewood. — Boil  4  pound  logwood  in  3  pints 
■water  till  it  is  of  a  very  dark  red;  add"  \  ounce  salt  of  tartar  'car- 
bonate of  potassa).  While  boiling  hot,  stain  the  wood  with  2  or 
3  coats,  taking  care  that  it  is  nearly  dry  between  each  ;  then, 
with  a  stiff  flat  brush,  siich  as  is  used  by  the  painters  for  grain- 
ing, form  streaks  with  the  black  stain  above  named  (see  last  re- 
ceipt), which,  if  carefully  executed,  will  be  very  nearly  the  aj)- 
pearance  of  dark  rosewood;  or,  the  black  streaks  may  be  put  in 
with  a  camel's  hair  pencil,  dijiped  in  a  solution  of  copperas  and 
verdigris  in  a  decoction  of  logwood.  A  handy  brush  for  the  pur- 
pose may  be  made  out  of  a  flat  bri;sh,  such  as  is  used  for  varnish- 
ing; cut  the  sharp  points  off,  and  make  the  edges  irregular,  by 
cutting  out  a  few  hairs  here  and  there,  and  you  will  have  a  tool 
■which  will  accurately  imitate  the  grain. 

To  polish  Varnish  is  certainly  a  tedious  process,  and  con- 
sidered by  many  as  a  matter  of  difficulty.  Put  2  ounces  pow- 
dered tripoli  into  an  earthen  pot  or  basin,  with  water  sufficient 
to  cover  it ;  then  with  a  piece  of  fine  flannel  four  times  doubled, 
laid  over  a  piece  of  cork  rubber,  proceed  to  polish  the  varnish, 
always  wetting  it  well  with  the  tripoli  and  water.  It  will  be 
known  when  the  process  is  complete  by  willing  a  part  of  the 
work  with  a  sponge,  and  observing  whether  there  is  a  fair  and 
even  gloss.  Clean  off  with  a  bit  of  mutton-suet  and  fine  flour. 
Be  careful  not  to  rub  the  work  too  hard,  or  longer  than  is  neces- 
sary to  make  the  face  jjerfectly  smooth  and  even. 

The  French  3Ietho<l  of  Polishing/.— V/iih  a  piece  of 
fine  pumice-stone  and  water  pass  regularly  over  the  work  with 
the  grain  until  the  rising  of  the  grain  is  down  ;  then,  with  pow- 
dered tripoli  and  boiled  linseed  oil,  polish  the  work  to  a  bright 
face.  This  will  be  a  very  superior  polish,  but  it  requires  con- 
siderable time. 


248  PRACTICAL   MECHANICAL   RECEIPTS. 

To  2)olitih Brass  Ornaments  inlaid  in  Wood.— The 

brass-work  must  first  be  tiled  very  even  with  a  smooth  file;  then, 
having  mixed  some  very  finely  powdered  tripoli  with  linseed 
oil,  polish  the  work  with  a  rubber  made  from  a  piece  of  old  hat 
or  felt,  as  you  would  polish  varnish,  until  the  desired  effect  is 
produced.  If  the  work  be  ebony,  or  black  rosewood,  take  some 
elder-coal,  powdered  very  fine,  and  apply  it  dry  after  you  have 
done  with  the  tripoli.      It  will  increase  the  beauty  of  the  polish. 

To  clean  Soft  Mali o(/an  if  or  other  Porous  Wood.— 

After  scraping  and  sand-papering  in  the  usual  manner,  take  a 
sponge  and  well  wet  the  surface,  to  raise  the  grain  ;  then,  with  a 
piece  of  fine  pumice-stone,  free  from  stony  particles,  and  cut  the 
way  of  the  filires,  rub  the  wood  in  the  direction  of  the  grain, 
keeping  it  moist  with  water.  Let  the  work  dry  ;  then  wet  it 
again,  and  the  grain  will  be  much  smoother,  and  will  not  raise 
so  much.  Eepeat  the  i)rocess,  and  the  grain  will  become  per- 
fectly smooth,  and  the  texture  of  the  wood  much  hardened.  _  If 
this  does  not  succeed  to  satisfaction,  the  surface  may  be  im- 
proved by  using  the  pumice-stone  with  cold-drawn  linseed  oil, 
proceeding  in  the  same  manner  as  with  water.  This  will  be 
found  to  give  a  most  beautiful  as  well  as  a  durable  face  to  the 
work,  which  may  then  be  polished  or  varnished. 

To  (Iran  and  finish,  Mahotjan if  .WorU.—^cra.T^6  and 

sanl-paper  the  work  as  smooth  as  possible  ;  go  over  every  part 
with  a  brush  dipped  in  furniture  oil,  and  let  it  remain  all  night; 
have  ready  the  powder  of  the  finest  red  brick,  which  tie  up  in  a 
cotton  stocking,  and  sift  equally  over  the  work  the  next  morn- 
ing, and,  with  a  leaden  or  iron  weight  in  a  piece  of  carpet,  rub  it 
well  the  way  of  the  grain,  backward  and  forward,  till  it  has  a 
good  gloss.  If  not  sufficient,  or  if  the  grain  appears  at  all 
rough,  repeat  the  process.  Be  careful  not  to  put  too  much  of  the 
bric"k-'dust,  as  it  should  not  be  rubbed  dry,  but  rather  as  a  paste 
upon  the  cloth.  When  the  surface  is  perfectly  smooth,  clean  it 
otfwith  a  rubber  of  carpet  and  fine  mahogany  sawdust.  This 
process  will  give  a  good  gloss,  and  make  a  surface  that  will  im- 
prove by  wear. 

To  clean  and,  polish  Old  Fi(rnitiire.—Tfike  a  quart 
of  stale  beer  or  vinegar,  put  a  liandful  of  common  salt  and  a 
table-spoonful  of  muriatic  acid  into  it,  and  boil  it  for  15  minutes; 
it  may  bo  kept  in  a  bottle,  and  warmed  when  wanted  for  use. 
Having  previously  washed  the  furniture  with  soft  hot  water,  to 
get  the  dirt  off,  wash  it  carefully  with  the  above  mixture  ;  then 
polish,  according  to  the  directions,  with  any  of  the  foregoing 
polishes. 

Composition  for  Soft  or  Lif/lit  Malioff an;/.— Boil 
togrther  coM-dniwii  liiiscrd  oil,  and  as  much  allcanct  root  as  it 
will  cover,  and  to  every  pint  of  oil  add  oik!  ounce  of  tlio  best 
rose  i>ink'  When  all  the  cohir  is  extracted,  strain  it  off,  and  to 
every  pint  add  J  gill  spirits  of  turp.'iitine.  This  will  bo  a  very 
superior  composition  for  soft  luul  light  mahogany. 


PEACTICAL    MECHANICAL   EECEIPTS.  249 

Mixture  fov  cleanhif/  Furniture. — Cold-drawn  linseed 
oil,  1  quart ;  spirits  of  wine  and  vinegar,  J  pint  each  ;  butter 
(terchloride)  of  antimonj-,  2  ounces;  sj^irits  of  turjsentine,  \  pint. 
This  mixture  requires  to  be  well  shaken  before  it  is  used.  A  lit- 
tle of  it  is  then  to  be  poui-ed  upon  a  rubber,  which  must  be  well 
applied  to  the  surface  of  the  furniture  ;  several  applications  will 
be  necessary  for  new  furniture,  or  for  such  as  had  previously 
been  French  polished  or  rubbed  with  bees'  wax. 

Furniture  Polish. — Dissolve  4  ounces  best  shellac  in  2 
pints  95  per  cent,  alcohol ;  add  to  this  2  pints  linseed  oil,  and  I 
pint  spirits  of  turi^entine  ;  when  mixed,  add  -t  ounces  sulphuric 
ether,  and  4  ounces  ammonia  water ;  mix  thoroughly.  Shake 
■when  used,  and  apply  with  a  sponge  lightly.  This  is  an  excel- 
lent article,  especially  where  the  varnish  has  become  old  and 
tarnished. 

Furniture  Polish — Bees'  wax,  i  pound;  alkanet  root, 
i  ounce  ;  melt  together  in  a  pipkin  untfl  the  former  is  well  col- 
ored. Ihen  add  linseed  oil  and  spirits  of  turpentine,  of  each 
J  gill ;  strain  through  a  jiiece  of  coarse  muslin. 

Furniture  Puste. — Turpentine,  1  pint  ;  alkanet  root,  \ 
ounce  ;  digest  until  sufficiently  colored,  then  add  bees'  wax, 
scraped  small,  4  ounces  ;  put  the  vessel  into  hot  water  and  stir 
until  dissolved.     If  wanted  pale,  the  alkanet  may  be  omitted. 

Pest  Frenrh  Polish. — Shellac,  3  parts  ;  gum  mastic,  1 
part ;  gum  sandarach,  1  part ;  spirits  of  wine,  40  parts ;  the 
mastic  and  sandarach  must  first  be  dissolved  in  the  spirits  of 
wine,  and  then  the  shellac  ;  the  process  may  be  performed  by 
putting  them  into  a  bottle  loosely  corked,  and  placing  it  in  a 
vessel  of  water  heated  to  a  little  below  173^  Fahr.,  or  the  boiling 
point  of  spirits  of  wine,  until  the  solution  be  effected  ;  the  clear 
solution  may  be  poureil  off  into  another  bottle  for  use.  Various 
receipts  for  the  French  polish  have  been  published,  in  which 
ingredients  are  inserted  that  are  insoluble  in  spirits  of  wine,  and 
therefore  useless;  and  others  contain  ingredients  that  are  soluble 
in  water,  so  as  to  render  the  mixture  more  easily  injured. 

'  To  WU.K  Furniture. — In  waxing,  it  is  of  great  importance 
to  make  the  coating  as  thin  as  possible,  in  order  that  the  veins 
of  the  wood  may  be  distinctly  seen.  The  following  prejiaration 
is  the  best  for  performing  this  operation  :  Put  2  ounces  white 
and  yellow  wax  over  a  moderate  fire,  in  a  very  clean  vessel,  and,  j 
when  it  is  quite  melted,  add  4  ounces  best  spirits  of  turpentine. 
Stir  the  whole  until  it  is  entirely  cool,  and  you  will  have  a  po- 
made fit  for  waxing  furniture,  which  must  be  rubbed  over  it 
according  to  the  usual  method.  The  oil  soon  penetrates  the 
pores  of  the  wood,  brings  out  the  color  of  it,  causes  the  wax  to 
adhere  better,  and  jDroduces  a  lustre  equal  to  that  of  varnish, 
without  being  subject  to  any  of  its  inconveniences.  The  polish 
may  be  renewed  at  any  time  by  rubbing  it  with  a  piece  of  fine 
cork. 

IX* 


250  PRACTICAL   MECHANICAL   RECEIPTS. 

To  French  JPolish. — The  varnish  being  prepared  (shellac), 
the  article  to  be  polished  being  finished  off  as  smoothly  as  possi- 
ble with  glass  pajjer,  and  the  rubber  being  made  as  directed 
below,  proceed  to  the  oijeration  as  follows  ;  The  varnish,  in  a 
narrow-necked  bottle,  is  to  be  applied  to  the  middle  of  the  flat 
face  of  the  rubber,  by  laying  the  rubber  on  the  mouth  of  tlie 
bottle  and  shaking  up  the  varnish  once,  as  by  this  means  the 
rubber  will  imbibe  the  projier  quantity  to  varnish  a  considerable 
extent  of  surface.  The  rubber  is  then  to  be  inclosed  in  a  soft 
linen  cloth,  doubled,  the  rest  of  the  cloth  being  gathered  up  at 
the  back  of  the  rubber  to  form  a  handle.  Moisten  the  face  of 
the  linen  with  a  little  raw  linseed  oil,  applied  with  the  finger  to 
the  middle  of  it.  Place  the  work  opposite  the  light,  pass  the 
rubber  quickly  and  lightly  over  its  surface  uniform!}'  in  small 
circular  strokes,  until  the  varnish  becomes  dry,  or  nearly  so  ; 
again  charge  the  rubber  as  before  with  varnish  (omitting  the 
oil),  and  repeat  the  rubbing,  until  three  coats  are  laid  on,  when 
a  little  oil  may  be  applied  to  the  rubber,  and  two  coats  more 
given  to  it.  Proceed  in  this  way  until  the  varnish  has  acquired 
some  thickness  ;  then  wet  the  inside  of  the  linen  cloth,  before 
applying  the  varnish,  with  alcohol,  or  wood  najjlitha,  and  rub 
quickly,  lightly,  and  uniformlj-,  the  whole  surface.  Lastly,  wet 
the  linen  cloth  with  a  little  oil  and  alcohol  without  varnish,  and 
rub  as  before  till  dr}'.  Each  coat  is  to  be  rubbed  until  the  rag 
appears  dry  ;  and  too  much  varnish  must  not  be  put  on  the  rag 
at  a  time.  Be  also  very  particular  in  letting  the  rags  be  very 
clean  and  soft,  as  the  polish  depends,  in  a  great  measure,  on  the 
care  taken  in  keeping  it  clean  and  free  from  dust  during  the 
operation.  If  the  work  be  porous,  or  the  grain  coarse,  it  will  be 
necessary  to  give  it  a  coat  of  clear  si/,e  previous  to  commencing 
with  the  polish  ;  and,  when  dry,  gently  go  over  it  with  vi>ry  fine 
glass  paper.  The  size  will  fill  up  the  i)ores,  and  prevent  the 
waste  of  the  ])olish,  by  being  absorbed  into  the  wood,  and  bo 
also  a  saving  of  considerable  time  in  the  ojieration. 

To  vial^c  a  Freiirh  Polish  Itubhrr. — Eoll  up  a  strip 
of  tliick  woolen  cloth  which  lias  been  torn  off,  so  as  to  form  a 
Boft  elixstic  edge.  It  should  form  a  coil,  from  1  to  3  inches  in 
diameter,  according  to  the  size  of  the- work.  This  rubber  is  to 
bo  securely  bound  with  tliread,  to  prevent  it  from  uncoiling 
•when  it  is  used. 

J'olishinf/  Paste. — Take  3  ounces  white  wax,  \  ounce  Ciw- 
tilesoaji,  I  gill  turpentine.  Shavo  the  wax  and  soap  very  fine, 
and  ]>ut  Iht-  wax  to  the  turpentine  ;  let  it  stand  21  hours  ;  then 
boil  the  soap  in  I  gill  water,  and  add  to  the  wax  and  turpentine. 
Tliis  has  been  highly  recomnn'nded. 

Sftiiddrtirh  French  J'olish—^hoUaG,  2  pounds;  mastio 
and  sandar.ieh  (botli  in  jiowder*,  of  eiudi  1  ounce  ;  copal  varni.sh, 
12  f)uii(;i's  ;  alcohol,  1  gallon.  All  the  above  are  made  in  the  cold 
by  fr<  quf^ntly  stirring  or  sliaking  the  ingredients  together  in  a 
well-cloKcd  bottle  or  other  vessel.  I'Yeuch  polish  is  used  without 
filtering. 


PRACTICAL   MEOHANICAL   RECEIPTS.  251 

French  Polish.  — To  1  pint  spirits  of  Avino  a  IJ  J-  ounce  gum 
shellac,  the  same  quantity  gum  lac,  and  ^  ounce  gum  sandarach; 
put  these  ingredients  into  a  stone  bottle  near  a  tire,  frequently 
shaking  it ;  when  the  various  gums  are  dissolved  it  is  fit  for  use. 

Fretwli  Polish. — Take  2  ounces  wood  naphtha,  \  ounce  best 
shellac,  1  dram  gum  benzoin;  crush  the  gums,  mix  them  with 
the  naphtha  in  a  bottle;  shake  them  frequently  till  dissolved;  it  is 
then  ready  for  use.  This  is  the  clear  polish.  Take  a  little  cot- 
ton wool,  apply  a  little  of  the  polish  to  it,  cover  it  tightly  with  a 
linen  rag,  to  which  apply  a  drop  of  linseed  oil,  to  jirevent  it  from 
sticking  to  the  wood;  use  your  rubber  gently,  polishing  from  a 
centre  in  a  circular  manner;  finish  with  a  droj)  of  spirits  of  wine 
on  a  clean  rubber,  which  will  extract  the  oik 

To  sta  in  or  color  French  Polish.— ^Vood  may  be  stained 
or  grained  any  color  or  design,  by  mixing  it  with  the  polish,  or 
dipping  the  rubber  in  the  color  t finely  powdered \  at  the  time 
you  apply  the  polish.  To  produce  a  rod,  dij)  the  cotton  into 
dragon's  blood  (finely  i^owdered),  immediately  apj^lying  the 
polish;  then  cover  with  the  linen,  and  polish.  For  yellow,  use 
the  best  chrome  yellow.  For  blue,  ultramarine  blue,  or  indigo. 
For  black,  ivory  or  lamp-black,  Ac.  Graining  is  produced  by 
touching  or  streaking  the  wood  with  the  color,  as  above,  in  ir- 
regular lines  or  marks,  and  in  such  shapes  as  the  fancy  may  sug- 
gest, then  finishing  it  with  a  coat  of  clear  polish. 

Water-Proof  Polish.— Take  1  pint  spirits  of  wine,  2  oz. 
gum -benzoin,  \  ounce  gum  sandarach,  and  \  ounce  gum  anime; 
these  must  be  put  into  a  stoppered  bottle,  and  placed  either 
In  a  sand-bath  or  in  hot  water  till  dissolved;  then  strain  the  mix- 
ture, and,  after  adding  about  \  gill  best  clear  poppy  oil,  shake  it 
well  up,  and  put  it  by  for  iise. 

BrigJif  Polish. — 1  pint  spirits  of  wine,  2  ounces  gum-ben- 
zoin, and  5  ounce  gum-sandarach,  put  in  a  glass  bottle  corked, 
and  placed  in  a  sand-bath  or  hot  water  until  you  find  all  the  gum 
dissolved,  will  make  a  beautiful  clear  polish  for  Tunbridgeware 
goods,  tea-caddies,  &c.  It  must  be  shaken  from  time  to  time, 
and,  when  all  dissolved,  strained  though  a  fine  muslin  sieve,  and 
bottled  for  use. 

Prepared  Spirits  for  Finishing  Poli.sh— This  prepa- 
ration is  useful  for  finishing  after  any  of  the  foregoing  recei^Dts,  as 
it  adds  to  the  lustre  and  durability,  as  well  as  removing  every 
defect,  of  the  other  polishes;  and  it  gives  the  surface  a  most  bril- 
liant appearance.  Take  J  pint  best  rectified  spirits  of  wine,  2 
drams  shellac,  and  2  drams  gum-benzoin.  Put  these  ingredients 
in  a  bottle,  and  keep  it  in  a  warm  place  till  the  gum  is  all  dis- 
solved, shaking  it  frequently;  when  cold,  add  2  tea-spoonfuls  of 
the  best  clear  white  l  opjiy  oil;  shake  them  well  together,  and  it 
is  fit  for  use.  This  preparation  is  used  in  the  same  manner  as 
the  foregoing  polishes;  but,  in  order  to  remove  all  dull  places, 
the  pressure  in  rubbing  may  be  increased. 


252  PllACTICAL  MECIIAXICAL  RECEIPTS. 

Ilrnv  to  {jh'C  lilacJc  Waluut  a  Darh  Dead  Smooth 
Siir/'(tce. — Take  asphaltiim,  pulverize  it,  place  it  in  a  jar  or 
bottle,  pour  over  it  about  twice  its  bulk  of  turpentine  or  benzole, 
jmt  it  in  a  warm  place,  and  shake  it  from  time  to  time.  V  hen 
dissolved,  strain  it  and  Jpply  it  to  tlie  wood  with  a  cloth  or  stiff 
brush.  If  it  should  make  too  dark  a  stain,  thin  it  with  turpen- 
tine or  benzole.  This  will  dry  in  a  few  hours.  If  it  is  des-ired 
to  bring  out  the  grain  still  more,  apply  a  mixture  of  boiled  oil 
and  turpentine;  this  is  better  than  od  alone.  Put  no  oil  with 
the  asphaltnm  mixture,  as  it  will  dry  very  slowly.  "When  the  oil 
is  dry  the  wood  can  be  polished  with  the  following:  Shellac  var- 
nish, of  the  usual  consistency,  2  parts;  boiled  oil,  1  part.  Shake 
it  well  before  using.  Ajiply  it  to  the  wood  by  putting  a  few  drops 
on  a  cloth  and  rubbing  briskly  on  the  wood  for  a  few  moments. 
This  polish  works  well  on  old  varnished  fuiniti;re. 

Polish  for  Tamers'  TFor/c— Dissolve  sandarach  in  spirits 
of  wine  in  the  proportion  of  1  oz.  sandarach  to  .',  junt  of  spirits; 
next  shave  bees'  wax,  1  oz.,  and  dissolve  it  in  a  sufficient  quan- 
tity of  spirits  of  turpentine  to  made  it  into  a  paste ;  add  the  lormer 
mixture  by  degrees  to  it;  then  with  a  woolen  cloth  apj  ly  it  to 
the  work  while  it  is  in  motion  in  the  lathe,  and  with  a  soft  linen 
rag  polish  it.     It  will  apjiear  as  if  highly  varnished. 

To  nrepare  the  FiUin(/-uj}  Color  for  eva'iueUhig 
IFooa.  — ihe  filling-up  color,  which  forms  the  body  of  the 
enamel,  is  of  the  greatest  importance  to  the  ultimate  success  of 
the  work.  Of  this  material  there  are  several  kinds  manulactured 
— black,  brown,  and  yellow,  for  coach  j  ainters,  jaj  annus,  and 
others;  but  for  use  in  interior  decoration  it  is  })reitralle  to  use 
the  white  lead  filling,  as,  by  adding  the  necessary  staining  colors 
(which  do  not  affect  the  properties  of  the  enamel),  a  solid  body 
of  color  is  formed,  of  the  same  tint,  or  nearly  so,  as  that  with 
wliich  the  woric  is  rc(iuired  to  be  finished,  thus  doing  away  with 
the  objections  that  may  be  urged  against  the  black  or  dark-col- 
ored tilling.  It  is  evident  that  if  work  which  has  to  be  linihlud 
white,  or  with  very  light  tints  of  color,  be  filled  np  with  dark- 
colored  filling,  the  number  of  coats  of  paint  required  to  obscure 
or  kill  the  dark  color  will  be  so  manj'  that  there  will  be  danger 
of  tlie  work  becoming  rough  and  uneven  in  parts.  The -white 
lead  should  be  ground  stiff  in  turpentine,  and  abo\it  one-f(jurth 
l)art  of  the  ordinary  white  Lad,  ground  in  oil  added  to  it.  in 
order  to  jirevent  the  enamel  cracking,  which  it  has  a  tendency 
to  do,  cxccjit  there  be  some  little  oil  mixed  with  it.  A  sufficient 
cjuantity  of  polishing  copal  or  best  carriage  varnish  she)ul(l  neiw 
bo  aebled  to  bind  it  so  that  it  will  rub  down  easily,  which  fact  e'an- 
not  be  properly  ascertained  exccjit  by  actual  trial,  inasmuch  as 
the  drying  ])roperties  of  varnislu^s  vary,  and  other  causes  influ- 
ence tlu!  matteT  Iffliere  be  too  much  varnish  in  the  stuff  the 
work  will  be  exijoedingly  dillicult  to  cut  down,  and  if  too  little, 
it  is  apt  to  break  up  in  rubbing,  so  that  it  is  always  the  safest 
)>lan  to  try  the  enamel  ce)lor  before  commencing  anything  im- 
pf)rtant. 


PRACTICAL   MECHANICAL   RECEIPTS.  253 

Strong  JPoUsJi. — To  bo  used  in  tlie  carved  parts  of  cabinet- 
■work  with  a  brush,  as  in  standards,  pillars,  claws,  &c.  Dissolve 
2  ounces  seed  lac  and  2  ounces  white  resin  in  1  jjint  spirits  of 
wine.  This  varnish  or  polish  must  be  laid  on  warm,  and  if  the 
work  can  be  warmed  also,  it  will  be  so  much  the  better;  at  any 
rate,  moisture  and  dampness  must  be  avoided. 

To   prepare   tlie  Pumice-Stone  for    enamelling 

Wood. — The  pumice-stone  to  be  used  should  be  of  different 
degrees  of  fineness,  and  should  be  carefully  selected,  so  as  to  be 
sure  that  it  is  free  from  any  gritty  substance.  It  is  sold  ready 
ground,  but  in  situations  where  it  cannot  be  readily  got,  it  may 
be  prepared  from  the  lump,  by  grinding  or  crushing  with  a  stone 
and  muUer,  and  then  passed  through  fine  sieves  or  muslin;  by 
using  these  of  different  degrees  of  texture  the  ground  pumice 
may  be  produced  of  different  degrees  of  fineness.  Unless  great 
care  be  exercised  in  this  matter,  it  will  be  found  that  particles  of 
grit  will  be  mixed  with  it,  vrhich  make  deep  scratches  on  the 
work,  thus  causing  endless  trouble  and  annoyance,  besides 
spoiling  the  work.  The  gr>?atest  care  is  also  required  in  keeping 
the  felt  clean  and  free  from  grit.  Many  workmen  are  careless 
in  this  matter,  and,  when  working,  set  down  the  felt  on  the  step- 
ladder  or  floor,  thus  allowing  particles  of  sand  or  grit  to  get 
upon  it. 

To  cut  down  or  jyrepare  the  Surface  for  poUshing. 

— In  cutting  down,  it  is  best  to  use  a  piece  of  soft  liimp  pumice 
stone  to  take  off  the  rough  parts.  The  work  should  then  be  wet 
with  a  sponge;  the  felt  must  first  be  soaked  in  water,  then  dipped 
into  the  powdered  pumice,  and  the  work  rubbed  with  it,  keeping 
it  moderately  wet,  and  rubbing  with  a  circular  motion,  not  straight 
up  and  down  and  across,  and  with  a  light  touch,  using  only 
just  as  much  pressure  as  will  cause  the  pumice  to  bite,  which 
vdW  be  very  clearly  felt  while  the  hand  is  in  motion.  Care  and 
patience  are  reqiiired  to  do  this  properly,  for  if  the  pressure  be 
too  great  it  forces  the  pumice  into  the  body  of  the  filling  color, 
and  scratches  it  instead  of  cutting  or  grinding  it  fairly  down.  No 
huiTy  will  avail  in  doing  this  work,  it  must  have  its  time;  hurry 
often  defeats  the  end  in  view,  and  often  causes  much  unneces- 
sary labor.  A  scratch,  caused  by  want  of  care  and  too  much 
haste,  will  often  thro\v  the  work  back  for  days,  and  involve  the 
cost  and  labor  of  refilling.  In  pi-actice  the  purpose  is  best  an- 
swered by  using  the  pumice-stone,  the  coarser  kind  first,  then 
the  medium,  and  finishing  with  the  finest  last.  It  will  be  found 
advantageous  to  let  a  day  elapse  between  the  nibbing,  for  when 
the  surface  is  cut  do%\-n  the  filling  will  in  all  cases  be  softer  un- 
derneath, and  if  it  be  allowed  to  stand  for  a  daj',  the  newly  ex- 
posed surface  gets  harder,  and  of  course  rubs  down  better.  The 
pumice-stone  shoiild  be  wel  washed  off  the  work  occasionally, 
in  order  to  see  what  progress  is  being  made,  and  if  it  require 
more  rubbing  or  not.  If,  after  the  first  nibbing,  the  surface  be 
found  not  suflicicntly  filled  up,  it  may  have  one  or  more  addi- 
tional coats  of  filling  before  much  labor  has  been  suent  ujion  it. 


2o\:  TRACTICAL  MECHANICAL  RECEIPTS. 

To  laif  the  Color  on  I^natnelled  Wood.—ThQ  color, 
boiug  properly  ruixeil,  shoulil  be  laid  ou  the  wtJrk  in  the  ordi- 
nary manner,  using  it  rather  freely.  It  may  be  as  well  to  state 
here  that  no  tilling  should  be  put  upon  new  work  without  the 
same  havin^^  had  2  or  3  coats  of  ordinary  oil  }  aint,  nor  on  old 
work  without  its  having  one  coat.  This  gives  a  foundation  for 
the  filling.  Successive  coats  of  the  filling  should  now  be  laid  on 
the  work  until  there  is  a  sufficient  thickness  to  cut  down  to  a 
level  surface.  One  day  should  intervene  between  each  coat,  in 
order  to  allow  it  to  harden  in  some  degree.  When  a  sufficient 
number  of  coats  are  put  on  (which  number  will,  of  course,  de- 
pend upon  the  state  of  the  work  to  be  filled  up),  it  should  stand 
for  2  or  3  weeks,  until  it  is  Ihoroiighly  hard;  it  will  then  be  ready 
for  cutting  down,  which  is  to  bo  done  with  a  felt  rubber,  ground 
pumice-stone,  and  water. 

To  prepare  the  liuhherfor  eiuunellhif/  IFood.—The 

felt  used  should  be  sucli  as  the  sculptoi'S  use  for  polishing  mar- 
ble, which  varies  in  thickness  from  J  to  ^  an  inch,  and  about  3 
inches  square.  This  should  be  fastened  with  resinous  gum  to 
square  pieces  of  wood  of  the  same  size,  but  1  inch  thick,  to  as  to 
give  a  good  hold  for  tho  hand  in  using.  These  pieces  of  wood 
covered  with  felt,  may  be  made  of  any  size  or  shape  to  fit  moulded 
surfaces  or  other  inequalities. 

Tinman's  Solder. — Lead,  1  part;  tin,  1  part. 

Pewterer's  Solder.— Tin,  2  parts;  lead,  1  part. 

Common  Pewter. — Tin,  4  parts;  lead,  1  i)art. 

Jiesf  Peivter. — ^Tin,  100  parts;  antimony,  17  parts. 

A  Metal  that  expands  in  rooZ/iu/.  -Lead,  9  parts;  an- 
timony, 2  parts;  bismutli,  1  part.  This  metal  is  very  useful  iu 
filling  small  defects  in  iron  castings,  Ac. 

Silrrr  Coin  of  the  United  States —Vnre  silver,  9  parts; 

alloy,  1  piut;  the  alloy  of  silver  is  line  copper. 

Cold  Coin  of  the  United  States.—Vnn^  gold.  0  parts; 
alloy,  1  ])ait;  tho  alloy  of  gold  is  ^  silver  and  J  copi)er  (not  to 
exceed  \  silver). 

Silver  Coin  of  (ireat  Jiritain.—I'xire  Hi\\er,  11.1  parts; 
copper,  0.9  part. 

Gold  Coin  of  flreat  Britain.— Vnro  gold,  11  parts;  cop- 
per, 1  ])art.  I'revious  to  ISJO  silver  formed  part  of  tlio  alloy  of 
gold  coin;  hence  tho  dill'i  rent  color  of  English  gold  money. 

Cast  Tron  Cement.— CAoAn  borings  or  turnings  of  cast  iron, 
Ki  jiarts;  sal-ammoniac,  2  i)arls;  lliMir  of  sulj)hur,  1  part;  mix 
them  well  together  in  a  mnrlar  and  keep  them  dry.  When  ro- 
qiiirtul  for  use,  talce  of  the  mixture,  1  ])art ;  clean  borings,  20 
parts;  mix  tiiorougldy,  and  add  a  Kuffieient  (juantily  of  water. 
A  little  grindstone-dust  added  improves  tho  cement. 


PRACTICAL    MECHANICAL    RECEIPTS.  255 

Queen's  3Iefal. — Tin,  9  laarls;  autimony,  1  part;  bismuth, 
1  part;  lead,  1  i:)art. 

Mode  Platbiuui. — Brass,  8  parts;  zinc,  5  parts. 

Booth's  Patent  Grease,  for  Railway  Axles. — Water,  1 
gal. ;  clean  tallow,  3  lbs. ;  palm  oil,  G  lbs. ;  common  soda,  J  lb. 

Or:  Tallow,  8  lbs. ;  palm  oil,  10  lbs.  The  mixture  to  be  heated 
to  about  210°  F.,  and  well  stirred  till  it  cools  down  to  about  70°, 
when  it  is  ready  for  use. 

Cement,  for  Steam-Pipe  Joints,  &c.,  vmn  r.ACED  Flanges. — 
White  lead,  mixed,  2  parts;  red  lead,  dry,  1  part;  grind  or  other- 
wise mix  them  to  a  consistence  of  thin  Jjutty,  ajiply  interposed 
layers  with  one  or  two  thicknesses  of  canvas  or  gauze  wire,  as  the 
necessity  of  the  case  may  be. 

Olive  Bronze  Dip,  for  Brass. — Nitric  acid,  3  ozs. ;  muri- 
atic acid,  2  ozs.;  add  titanium  or  palladium;  when  the  metal  is 
dissolved,  add  2  gals  pure  soft  water  to  each  pint  of  the  solution. 

Brown  Bronze  Paint,  for  Copper  Vessels. — Tincture  of 
steel,  4  ozs. ;  siiirits  of  nitre,  4  ozs;  essence  of  dendi,  4  ozs.;  blue 
vitriol,  1  oz. ;  water,  ^  pint.  Mix  in  a  bottle.  Apply  it  with  a 
fine  brush,  the  vessel  being  full  of  boiling  water.  Varnish  after 
the  application  of  the  1  ronze. 

Bronze,  for  all  Kinds  of  Metal. — Muriate  of  ammonia  (sal- 
ammoniac  ,  '1  drs. ;  oxalic  acid,  1  dr.;  vinegar,  1  pint.  Dissolve 
the  oxalic  acid  first.  Let  the  work  be  clean.  Put  on  the  bronze 
with  a  brush,  repeating  the  operation  as  many  times  as  may  be 
necessary. 

Bronze  Paint,  for  Iron  or  Brass. — Chrome  green,  2  lbs.; 
ivo  y  black,  1  oz. ;  chrome  yellow,  1  oz. ;  good  japan,  1  gill;  grind 
all  together  and  mix  with  linseed  oil. 

To  bronze  Crim-Barrels. — Dilute  nitric  acid  with  water 
and  rub  the  gun-barrels  with  it;  lay  them  by  for  a  fow  days,  then 
rub  them  with  oil,  and  polish  them  with  bees-wax. 

For  tinning  Brass. — Water,  2  i^ailfuls;  cream  of  tartar,  ^ 
lb. ;  salt,  \  pint.  Shaved  or  Grained  Tin — Boil  the  work  in  the 
mixture,  keeping  it  in  motion  during  the  time  of  boiling. 

Silverinf/  hy  Heat. — Dissolve  1  oz.  of  silver  in  nitric  acid  ; 
add  a  small  q.iiuitity  of  salt;  then  wash  it  and  add  sal-ammoniac 
or  6  oz.  of  salt  and  white  vitriol;  also  \  oz.  of  corrosive  subli- 
mate; rub  them  together  till  they  form  a  paste,  rub  the  i^iece 
which  is  to  b  3  silvere  1  with  the  paste,  heat  it  till  the  silver  runs, 
after  which  dip  it  in  a  weak  vitriol  jjickle  to  clean  it. 

31ixtHre  for  Silverinfj. — Dissolve  2  ozs.  of  silver  with  3 
grains  of  corrosive  sublimate;  add  tartaric  acid,  -ilbs. ;  salt,  8  qts. 

SolveTtt  for  Gold — Mix  equal  quantities  of  nitric  and  mu- 
riatic acids. 


256  PRACTICAL   MtlCHANICAL   RECEIPTS. 

To  separate  Silver  from  C'oy>y;f'i'.— Mix  sulphuric  acid, 
1  part;  nitric  acid,  1  part;  water,  1  part;  boil  the  metal  in  the 
mixture  till  it  is  dissolved,  and  throw  in  a  little  salt  to  cause 
the  silver  to  subside. 

1't'irnisli,  FOB  SMOOTH  Moulding  Patterns. — Alcohol,  1  pil ; 
shellac,  1  lb. ;  lamp  or  ivory  black,  siifficient  to  color  it. 

FinrlildcJc  Frti'J* Is/*,  fok  Coaches.  -?>Ht,  in  an  iron  ]>ot, 
amber,  32  ozs. ;  resin,  6  ozs. ;  aspluiltuni.  0  o;«;  drying  linseed 
oil,  1  pt  ;  when  partlj'  cooled,  add  til  of  turpentine,  wormed, 
Ipt. 

Chinese  White  Copper. — Copper,  40.4  parts;  nickel,  31. G 
parts;  zinc,  2.5.4  parts,  and  iron,  2.6  parts. 

3I(itth('iin  Gold. — Copper,  3  parts;  zinc,  1  part,  and  a  small 
quantity  of  tin. 

Alloij  of  the  Stmulard  Measnre.<i  used  by  the  lirif- 
isjt  Oorcrnment. — Copper,  576  parts;  tin,  5'J  jmrts,  and 
brass,  48  parts. 

Until,  3Iet(tl. — Bra.ss,  32  parts,  and  zinc,  9  pai-ts. 

Spernlnni  3Iet(il. — Copper,  6  parts;  tin,  2  j'l^rts,  and 
arsenic,  1  part.  Or:  Copper,  7  jiarts;  zinc,  3  parts,  and  tin  4 
l)arts. 

Hard  Solder. — Copper,  2  parts;  zinc,  1  part. 

UlaiU'hed  Copper. — Copper,  8  parts,  and  arsenic,  \  part. 

lirit<(nnia  JMLetal. — Brass,  4  parts;  tin,  4  jmrts  ;  when 
fused,  add  bismuth,  4  parts,  and  antimony,  4  parts.  This  com- 
position is  added  at  discretion  to  melted  tin. 

Yellotr  Solder,  for  Brass  or  Copper. — (Stromjer  than  that  on 
ixi'je  244.) — Copper,  32  lbs.;  zinc,  29  lbs.;  tin,  1  lb. 

Solder,  for  Copper.— Copper,  10  lbs.;  zinc,  9  lbs. 

Ulcu'lc  Solder. — Copper,  2  lbs. ;  zinc,  3  lbs. ;  Tin,  2  ozs. 

Slaeh  Solder. — Sheet  brass,  20  lbs.;  tin,  G  lbs.;  zinc,  1  lb. 

Soft  Solder.— Tin,  15  lbs.;  lead,  15  lbs. 

Sitrcr  Sohler,  for  Pitted  IiIetal. — Fine  silver,  1  oz. ;  brass, 
10  pwts. 

Y'Uoin  Dippimj  Metal.— Gom-tei,  32  lbs.;  zinc,  2  lbs.; 
soft  solder,  2;^  ozs. 

Quirk  lififflit  Dippiin/  Arid,  for  Br.vss  wnicH  has  meen 
ORMoi.tiKi).      Sulphuric  acid,  1  t^al. ;  nitric  acid,  1  gal. 

Orinola  Dippimj  .irid,  for  Sheet  Brass. — Suli)huric 
acid,  2  gals.;  nitric  aciil,  1  j)l.;  muriatic  acid,  1  ])t. ;  water,  1  i)t. ; 
nitre,  12  lbs.  Put  in  the  muriatic  acid  last,  u  little  at  a  lime  and 
Btir  tbo  mixture  with  a  stick. 


PKACTICAL   MECHANICAL   RECEIPTS.  257 

Ormolu  Dipping  Acid,  for  Sheet  on  Caht  Beass. — Sul- 
phuric acid,  1  gal.;  sal-ammoniac,  1  oz. ;  sulphur  (in  flour),  1 
oz. ;  blue  vitriol,  1  oz. ;  saturated  solution  of  zinc  in  nitric  acid, 
mixed  with  an  equal  quiintity  of  sulphuric  acid,  1  gal. 

DippinfJ  A.cid. — Sulphuric  acid,  12  lbs.;  nitric  acid,  I  pint; 
nitre,  4  lbs. ;  soot,  2  handt'uls,  brimstone,  2  ozs.  Pulvei'ize  the 
brimstone  and  soak  it  in  water  an  hour.    Add  the  nitric  acid  last. 

Good  Jyippiug  JLcid,  foe  Cast  Bkass. — Sulphuric  acid,  1 
qt. ;  nitre,  1  qt. ;  water,  1  qt.  A  little  muriatic  acid  may  be  add- 
ed or  omitted. 

Dipping  Acid. — Sulphuric  acid,  4  gals. ;  nitric  acid,  2  gals. ; 
saturated  solution  of  sulphate  of  iron  (copperas),  1  pint:  solu- 
tion of  sulphate  of  copper,  1  qt. 

To  prepare  Brass  WorU  for  Ormolu  Dipping. — If 

the  work  is  oily,  boil  it  in  Ij-e;  and  if  it  is  finished  work,  filed  or 
turned,  diji  it  in  old  acid,  and  it  is  then  ready  to  be  ormolued; 
but  if  it  is  unfinished,  and  free  from  oil,  pickle  it  iu  strong  sul- 
phuric acid,  dip  in  pure  nitric  acid,  and  then  iu  the  old  acid, 
after  which  it  will  be  ready  for  ormoluing. 

To  repair  old  Xitrie  Acid  Or moJ ii  Di pa.— If  the  work 
after  dipping  appears  coarse  and  spotted,  add  vitriol  till  it  answers 
the  purpose.  If  the  work  after  dipping  appears  too  smooth,  add 
muriatic  acid  and  nitre  till  it  gives  the  right  appearance. 

The  other  ormolu  dips  should  be  repaired  according  to  the  re- 
ceipts, putting  in  the  jii'oper  ingredients  to  strengthen  them. 
They  should  not  be  allowed  to  settle,  but  should  be  stirred  often 
while  \ising. 

Tinning  Acid,  tor  Beass  or  Zinc— Muriatic  acid,  1  qt. ; 
zinc,  6  ozs.  To  a  solution  of  this  add,  water,  I  qt. ;  sal-am- 
moniac, 2  ozs. 

I'inegar  Jironze,  tor  Beasss.  - -Vinegar,  10  gals.;  blue  vit- 
riol, 3  lbs. ;  muriatic  acid,  3  lb.s. ;  corrosive  sublimate,  i  grs. ; 
sal-ammoniac,  2  lbs. ;  alum,  8  ozs. 

Directions  for  inalxing  Lacquer. — Mix  the  ingredients 
and  let  the  vessel  containing  them  stand  in  the  sun  or  in  a  place 
slightly  warmed  three  or  four  days,  shaking  it  frequentlj'  till  the 
giam  is  dissolved,  after  which  let  it  settle  from  twenty-four  to 
forty-eight  hours,  when  the  clear  liquor  may  be  poured  ntf  for 
use.  Pulverized  glass  is  sometimes  ^^sed  in  making  lacquer,  to 
carry  down  the  impurities. 

Lacquer,  for  dipped  Brass. — Alcohol,  proof  specific  gravity 
not  less  than  95-100,  2  gals. ;  seed  lac,  1  lb. ;  gum  copal,  I  oz. ; 
English  saffron,  1  oz. ;  annotto,  1  oz. 

Good  Lacquer,  for  Brass. — Seed  lac,  6  oz. ;  amber  or  copal, 
2  ozs. ;  best  alcohol,  4  gals. ;  pulverized  g'ass,  4  ozs. ;  dragon's 
blood,  40  grs. ;  extract  of  red  sandal  wood  obtained  by  water,  30 
grs. 


258  PRACTICAL   MECHANICAL   RECEIPTS. 

Lacquer,  fob  Bkonzed  Beass. — To  one  piut  of  the  above 
liic(iucr,  add  gamboge,  1  oz. ;  and  after  mixing  it  add  an  equal 
quantity  of  the  first  lacquer. 

Deep  Gold  Colored  Laeqner.—Bof^t  alcohol,  40  ozs. ; 
Spanish  annotto,  8  grs. ;  turmeric,  2  drs. ;  shi-llac,  ^  oz. ;  red  San- 
ders, 12  grs. ;  -when  dissolved  add  spirits  of  turpentine  3U  drops. 

Gold  Colored  Laeqiier,  for  Brass  not  Dipped. — Alcohol, 
4  gals. ;  tumeric,  3  lbs. ;  gamboge,  3  ozs. ;  gum  sandarach,  7  lbs. ; 
shellac,  l\  lb. ;  turpentine  A-arnish,  1  pint. 

Gold  Colored  Laequer,  for  Dipped  Br,vss. — Alcohol,  30 
ozs. ;  seed  lac,  6  ozs. ;  amber,  2  ozs. ;  gum  gutta,  2  ozs. ;  red  san- 
dal wood,  2 1  grs. ;  dragon's  blood,  GO  grs. ;  oriental  saftron,  36 
grs. ;  pulverized  glass,  4  ozs. 

Laeqiier,  fob  Dipped  Brass. — Alcohol,  12  gals.;  seed  lac,  9 
lbs. ;  tumeric,  1  lb.  to  a  gallon  of  the  above  mixture;  Sjianish  saf- 
fron, 4  ozs.     The  saffron  is  to  be  added  for  bronze  work. 

iniifeivashfor  Oiif-Door  Use.— Take  a  clean  water-tight 
barrel  or  other  suitable  cask,  and  put  into  it  J  bushel  of  lime. 
Slack  it  by  pouring  boiling  water  over  it,  and  in  sufficient  qusm- 
tity  to  cover  5  inches  deej),  stirring  it  briskly  till  thoroughly 
slacked.  When  slacking  has  been  effected,  dissolve  in  water  and 
add  2  povmds  sulphate  of  zinc  and  1  of  common  salt.  These  will 
cause  the  wash  to  harden  and  prevent  it  from  cracking,  which 
gives  an  unseemly  ap2)earance  to  the  work.  If  desirable,  a  beau- 
tiful cream  color  may  be  communit'ated  to  the  above  wash,  bv 
adding  3  pounds  yellow  ochre.  This  wash  may  be  applied  with 
a  common  whitewash  brush,  and  will  be  found  much  superior, 
both  in  appearance  and  durability,  to  common  whitewash, 

Treasiiri/  Jh-partiueiit   ll'hifeirash.— This  receipt  for 

whitewashing,  sent  out  by  the  Liglit-house  Board  of  tin;  Treasury 
Department,  has  been  found,  by  experience,  to  answer  on  wood, 
brick,  and  stone  nearly  as  well  as  oil  paint,  and  is  much  cheaper. 
Slack  1  bushel  un.slacked  lime  with  boiling  water,  k<epiiig  it 
covered  during  the  process.  Strain  it,  and  add  a  peek  ol  salt, 
dissolvd  in  warm  water:  3  pounds  ground  rice,  jnit  in  boiling 
water  and  boilc(l  to  a  thin  paste;  \  j)ound  ])owdered  Spanish 
whiting,  and  a  ])()und  of  eh  ar  glue,  dissolved  in  warm  water; 
mix  th(!se  well  together,  and  let  the  mixture  stand  for  several 
days.  Keep  the  wash  tlius  prepared  in  a  ketth;  or  j)ortable  fur- 
nace, and  when  used  put  it  on  as  hot  as  iiossiblo  with  painters' 
or  whitewash  brushes. 

Flre-l*roof'  H'liifeirash.—Miiko  ordinary  whitewash  and 
ad<l  1  part  silicate  of  soda  (or  jjotash)  to  every  5  i)arts  of  the 
whitewash. 

Whifi-iraHh  for  Feiieesitr  (hi t - li iiild i nqs.  —  i^\ncV  tho 

lime  in  boiling  water,  and  to  3  gallons  ordinary  wliitewasli  a<ld  1 
pint  molasses  and  I  pint  table  salt.  Stir  the  mixture  frequently 
V.  hilo  putting  it  on.     Two  thin  coats  arc  sufficient. 


PEACTICAL   MECHANICAL   RECEIPTS.  259 

To pvepat'c  Kalsouiiiie. — Kalsomine  is  composed  of  zinc 
white  mixed  with  water  and  glue  sizing.  The  surface  to  whicli  it 
is  applied  must  be  clean  and  smooth.  For  ceilings,  mix  ^  pound 
glue  with  15  pounds  zinc;  for  walls,  1  pound  glue  with  15  pounds 
zinc.  The  glue,  the  night  before  its  use,  should  be  soaked  in 
water,  and  in  the  morning  liquefied  on  the  fire.  It  is  difficult  to 
]>repare  or  apply  kalsomine;  few  painters  can  do  so  successfullj- 
Paris  white  is  often  made  use  of  for  it,  but  it  is  not  the  genuine 
article.  (See  next  receipt. )  The  kaisomining  mixture  may  be 
colored  to  almost  any  required  tint,  by  mixing  appropriate  col- 
oring matter  with  it. 

To  Jxalsoiniup-  Jfalls. — In  case  the  wall  of  a  room,  say  16 
by  2)  feet  square,  is  to  be  kalsomined  with  two  coats,  it  will  re- 
quire \  pound  light-colored  glue  and  5  or  C  pounds  Paris  white. 
(See  last  receipt.)  Soak  the  glue  overnight  in  a  tin  vessel  con- 
taining about  a  quart  of  warm  water.  If  the  kalsomine  is  to  be 
applied  the  next  day,  add  a  pint  more  of  clean  water  to  the  glue, 
and  set  the  tin  vessel  containing  the  glue  into  a  kettle  of  boiling 
water  over  the  fire,  and  continue  to  stir  the  gliie  until  it  is  well 
dissolved  and  quite  thin.  If  the  glue-pail  be  placed  in  a  kettle 
of  boiling  water,  the  glue  will  not  be  scorched.  Then,  after  put- 
ting the  Paris  white  into  a  large  water-pail,  jiour  on  hot  water, 
and  stir  it  until  the  liquid  appears  like  thick  milk.  Now  mingle 
the  glue  liquid  with  the  whiting,  stir  it  thoroughly,  and  apply  it 
to  the  wall  with  a  whitewash-briish,  or  with  a  large  paint-brush. 
It  is  of  little  consequence  what  kind  of  an  instrument  is  employed 
in  laying  on  the  kalsomine,  provided  the  litpiid  is  spread  smooth- 
ly. Expensive  brushes,  made  expressly  for  kalsomining,  maj'  be 
obtained  at  brush  factories  and  at  some  drug  and  hardware 
stores.  But  a  good  whitewash-brush,  having  long  and  thick 
hair,  will  do  very  well.  In  case  the  liquid  is  so  thick  that  it  will 
not  flow  from  the  brush  so  as  to  make  smooth  work,  add  a  little 
more  hot  water.  When  aj^plying  the  kalsomine,  stir  it  fre- 
quently. Dip  the  brush  often,  and  only  so  deep  in  the  liquid 
as  to  take  as  much  as  the  hair  will  retain  without  letting  large 
drops  fall  to  the  floor.  If  too  much  glue  be  added,  the  kalso- 
mine cannot  be  laid  on  smoothly,  and  will  be  liable  to  crack. 
The  aim  should  be  to  apply  a  thin  layer  of  sizing  tliat  cannot  be 
brushed  off"  with  a  liroom  or  dry  cloth.    A  thin  coat  will  not  crack. 

A  Fine  IFJtitcwash  for  Walls. — Soak  |-  pound  of  glue 
ovei'night  in  tepid  water.  The  next  day  put  it  into  a  tin  vessel 
with  a  qiiart  of  water,  set  the  vessel  in  a  kettle  of  water  over  a 
fire,  heep  it  there  till  it  boils,  and  then  stir  till  the  glue  is  dis- 
solved. Next  put  from  6  to  8  pounds  Paris  white  into  another 
vessel,  add  hot  water,  and  stir  until  it  has  the  appearance  of  milk 
of  lime.  Add  the  sizing,  stir  well,  and  apply  in  the  ordinary 
way.  while  still  warm.  Except  on  very  dark  and  smoky  walls 
and  ceilings,  a  single  coat  is  sufficient.  It  is  nearly  equal  in  bril- 
liancy to  zinc-white  (a  far  more  expensive  article),  and  is  very 
highly  recommended  by  those  who  hiwe  used  it  Paris  white  is 
sulphate  of  baryta,  and  may  be  found  at  any  drug  or  paint  store. 


260  PRACTICAL   MECHANICAL   KECEIPTS, 

1o  color  jyhiieiVflsJi. — Coloring  matter  may  be  put  in  and 
made  of  any  shade.  iSpanisli  brown  stirred  in  will  make  red  pink, 
more  or  less  deep  according  to  the  quantity.  A  delicate  tinge 
of  this  is  very  pretty  for  inside  walls.  Finely  pulverized  com- 
mon clay,  -well  mixed  with  Spanish  brown,  luakes  a  reddish  stone 
color.  Yellow  ochre  stirre  1  in  makes  a  yellow  wash,  but  chrome 
goes  further  and  makes  a  color  generally  esteemed  prettier.  In 
all  these  cases  the  darkness  of  the  shades  of  course  is  determined 
by  the  quantity  of  coloring  used.  It  is  difficult  to  make  rules, 
because  tastes  are  different;  it  would  be  best  to  try  experiments 
on  a  shingle  and  let  it  dry.  Green  must  not  be  mixed  with  lime. 
The  lime  destroys  the  color,  and  the  color  has  an  effect  on  the 
whitewash,  which  makes  it  crack  and  peel.  "When  walls  have 
been  badly  smoked,  and  you  wish  to  have  them  a  clean  white,  it 
is  well  to  squeeze  indigo  plentifully  through  a  bag  into  the  water 
you  use,  before  it  Ls  stirred  in  the  whole  mixture. 

WUitt'ii'dsh  fov  Outside  irorJ^.—Tuke  of  good  quick- 
lime i  a  bushel,  slack  in  the  usual  manner,  and  add  one  pound 
common  salt,  I  pound  sulphate  of  zinc  (white  vitriol \  and  1  gal- 
lon sweet  milk.  The  salt  ami  the  white  vitriol  should  be  dis- 
solved before  they  are  added,  when  the  whole  shoiild  be  thor- 
oughly mixed  with  sufficient  water  to  give  the  proper  consist- 
ency.    The  sooner  the  mixture  is  then  applied  the  better. 

To  niljc  Whitewash.— PovLT  boiling  water  on  unslacked 
lime,  and  stir  it  occasionally  while  it  is  slacking,  as  it  will  make 
the  paste  smoother.  To  1  peck  of  lime  add  a  quart  of  salt  and  J 
ounce  of  indigo  dissolved  in  water,  or  the  same  (quantity  of  Prus- 
sian blue  finely  powdered;  aid  water  to  make  it  the  proper 
thickness  to  put  on  a  wall.     One  pound  soap  will  give  gloss. 

To  keep  jyhiteivash.—Kecp  the  lime  covered  with  water 
and  in  a  tub  which  has  a  cover,  to  prevent  dust  or  dirt  from  fall- 
ing in.  If  the  water  evaporates  the  lime  is  useless,  but  if  kept 
covered  it  will  be  good  as  long  as  any  remains. 

To  whiten  Smoked  Walls,  -k  method  of  cleaning  and 
whit<ning  smoked  walls  consists,  in  the  first  place,  of  rubbing 
off  all  the  black,  loose  dirt  upon  them,  by  means  of  a  broom,  and 
then  washing  them  down  with  a  strong  soda  lye,  which  is  to  be 
afterward  removed  by  means  of  water  to  which  a  little  hydro- 
chloric aeid  has  been  added.  When  the  walls  are  dry  a  thin 
coating  of  lime,  with  the  addition  of  a  solution  of  alum,  is  to  bo 
applie  1.  After  this  has  become  jierfectly  dry  tlu^  walls  are  to  bo 
kalsomined  or  coated  with  a  solution  of  glue  and  chalk. 

To  color  and  itrerrtif  Wh  iteirash  rahbiiuj  «/^".— Alum 
is  one  of  the  best  additions  to  make  whitewash  of  lime  which 
will  not  rub  off.  When  powdered  chalk  is  used,  glue  water  is? 
also  good,  but  would  not  do  for  outside  work  ixposed  to  much 
rain.  Nothing  is  easier  than  to  give  it  any  desired  color  by  small 
quantities  of  lamp-black,  brown  sienna,  ochre,  or  other  coloring 
matoriaL 


PRACTICAL   MECHANICAL   RECEIPTS.  261 

ZilhC  TFJiife wash— Mix  oxide  of  zinc  with  common  size, 
and  applj'  it  with  a  whitewash-brush  to  the  ceiling.  After  tliis, 
apply  in  the  same  manner  a  wash  of  chloride  of  zinc,  which  will 
combine  with  the  oxide  to  form  a  smooth  cement  with  a  shining 
surface. 

To  jioper  U'hifewasJied  Walls.— The  following  method 
is  simple,  sure,  and  inexpensive:  Make  flour  starch  as  you  Mould 
for  starching  calico  clothes,  and  with  a  whitewash-brush  wet  the 
wall  you  wish  to  paper  with  the  starch;  let  it  dry;  then,  when 
you  wish  to  apply  the  paper,  wet  the  wall  and  pa'per  both  with 
the  starch,  and  apply  the  paper.  Walls  have  been  papered  in 
this  way  that  have  been  whitewashed  10  or  even  20  years  succes- 
sively, and  the  paper  has  never  failed  to  stick.  When  you  wish 
to  re-paper  the  wall,  with  the  brush  wet  the  paper  with  clear 
water,  and  it  will  come  off  readily. 

Hed  Wash  for  Bricks.— To  remove  the  green  that  gathers 
on  bricks,  pour  over  the  bricks  boiling  water  in  which  any  vege- 
tables (not  greasy)  have  been  boiled.  Do  this  for  a  few  days  suc- 
cessively, and  the  green  will  disappear.  For  the  red  wash  melt 
1  ounce  of  glue  in  a  gallon  of  water;  while  hot  put  in  a  piece  of 
alum  the  size  of  an  egg,  J  pound  Venetian  red,  and  1  pound  Span- 
ish brown.  Try  a  little'on  the  bricks,  let  it  dry,  and  if  too  light 
add  more  red  and  brown;  if  too  dark,  put  in  more  water.  This 
receipt  was  contributed  by  a  person  who  has  used  it  for  20  years 
with  perfect  success. 

Waterproof  Mastic  Cement.  —Mix  together  1  part  red- 
lead  to  5  parts  ground  lime,  and  5  parts  sharp  sand,  with  boiled 
oil.  Or  :  1  part  red-lead  to  5  whiting  and  10  sharp  sand  mixed 
with  boiled  oil. 

Masons'  Cement  for  coating  the  Insides  of  Cis- 
terns.— Take  equal  parts  of  quicklime,  pulverized  baked  bricks, 
and  wood  ashes.  Thoroughly  mix  the  above  substances,  and 
dilute  with  sufficient  olive  oil  to  form  a  manageable  paste.  This 
cement  immediately  hardens  in  the  air,  and  never  cracks  beneath 
the  water. 

Fine  Stuff  for  Plastering.— Thin  is  made  by  slacking 
lime  with  a  small  portion  of  water,  after  which  sufficient  water  is 
added  to  give  it  the  consistence  of  cream.  It  is  then  allowed  to 
settle  for  some  time,  and  the  superfluous  water  is  i^oured  off,  and 
the  sediment  suffered  to  remain  till  evaporation  reduces  it  to  a 
proper  thickness  for  use.  For  some  kinds  of  work  it  is  necessary 
to  add  a  small  portion  of  hair. 

Higgins'  Stucco.— To  15  pounds  best  stone  lime  add  14 
pounds  bone  ashes,  finely  powdered,  and  about  95  pounds  clean, 
washed  sand,  quite  dry,  either  coarse  or  fine,  according  to  the 
nature  of  the  work  in  hand.  These  ingredients  must  be  inti- 
mately mixed,  and  kept  from  the  air  till  wanted.  "When  required 
for  use,  it  must  be  mixed  up  into  a  proper  consistence  for  work- 
ing with  lime  w^ater,  and  used  as  speedily  as  possibly. 


262  PRACTICAL   MECHANICAL   RZCEiPTS. 

Marble  JForhers'  Cement. -Flowev  of  sulphur,  1  part; 
hydrochlorate  of  ammonia,  2  parts  ;  iron  tilings,  IG  parts.  'Ihe 
above  substances  must  be  reduced  to  a  powder,  and  securely 
preserved  in  closely  stopped  vessels.  When  the  cement  is  to  be 
employed,  take  20  parts  very  fine  iron  filings,  add  1  part  ot  the 
above  powder,  mix  them  together  with  enough  water  to  form  a 
manageable  paste.  This  pastj  solidifies  in  2j  days  and  becomes 
as  hard  as  iron. 

Poi'thind  Cement.— Vovi\sim\  cement  is  formed  of  clay 
and  limestone,  generally  containing  some  silica,  the  properties 
of  which  may  vary  without  injury  to  the  cement.  The  propor- 
tion of  clay  may  also  vary  from  I'J  to  25  per  cent,  without  detri- 
ment. The  only  necessary  condition  for  the  formation  of  a  good 
artificial  Portbmd  cement,  is  an  intimate  and  homogeneous  mix- 
ture of  carbonate  of  lime  and  clay,  the  proportion  of  clay  being 
as  above  stated.  The  materials  are  raised  to  a  white  heat  in 
kilns  of  the  proper  form,  so  that  they  are  almost  vitrified.  After 
thj  calcination  all  pulverulent  and  scorified  portions  are  care- 
f.illy  pricked  out  and  thrown  away.  The  remainder  is  then 
finely  ground  and  becoines  readv  for  use.  The  amount  of  water 
v.hich  enters  into  combination  with  it  in  mixing  is  about. 3f)G  by 
weight.  It  sets  slowly,  from  12  to  18  hours  being  required. 
Made  into  a  thin  solution  lil:e  whitewash,  this  cement  gives 
woodwork  all  the  appearance  of  having  been  painted  and  sanded. 
Piles  of  stone  may  beset  together  with  common  mortar,  and  then 
t'ic  whole  washed  over  with  this  cement,  making  it  look  like  one 
immense  rock  of  gra}'  sandstone.  For  temporary  use  a  flour- 
barrel  ruay  have  the  hoops  nailed,  and  the  inside  washed  with  a 
Uttl3  Portland  cement,  and  it  will  do  for  a  year  or  more  to  hold 
w£:tor.  Boards  nailed  together,  and  washed  v.-ith  it,  make  good 
hot-water  tanks.  Its  water-resisting  properties  make  it  usefui 
for  a  variety  of  purposes. 

Stnreo  for  TnsliJe  of  Ifdlls. — This  stucco  consists  of  Js 
parts  line  stiilf  and  1  part  fiiK^  waslied  sand.  Those  i)arts  ol 
inteuior  walls  whicli  are  intended  to  be  painted  are  finished  with 
this  stucco.  In  using  this  material,  crcat  care  must  bo  taken 
that  the  surface  bo  perfectly  level,  and  to  secure  this  it  must  bo 
well  worked  with  a  floating  tool  or  wooden  trowel.  This  is  dono 
by  sprinkling  a  little  water  occasionally  on  tlie  stucco,  and  rib- 
liiiig  it  in  a  circular  diri'ction  with  tlie  float,  till  the  surfu-e  lias 
attain!' 1  a  high  gloss.  The  durability  of  the  work  much  depends 
upon  lio"'  it  is  done,  for  if  not  thoroiighly  worked  it  is  apt  to 
crack. 

AV.7'  PUistic  Material. — .\  beautiful  plastic  substjvnce  can 
bo  prepared  ly  mixing  collodion  with  phosphate  f)f  limo.  Tho 
])hosphato  should  bo  pure,  or  the  color  of  tlie  compinind  will  be 
nnsutisfactory.  On  Betting,  tho  mass  is  found  to  bo  hard  and 
Husceptibln  of  a  very  fine  ))olisli.  Tlu;  material  can  bo  used 
extensively.  ap]>lied  in  i:i()dcs  that  will  suggest  themselves  to  any 
intolliyont  artist,  to  high-cla.ss  decoration 


PllACTICAL   MECHANICAL   RECEIPTS.  263 

Dtirnhir  Coinptpnitioii  fov  Ornaments. — This  is  fre- 

qaiiULJy  use  1,  instead  ot  plaster  of  Pims,  tor  the  ornamentaJ 
parts  oi  builaings,  as  it  is  more  durable,  and  becomes  in  time  as 
bard  as  stone  itself.  It  is  of  great  use  in  the  execution  of  the 
decorative  parts  of  architecture,  and  also  in  the  finishings  of 
pictui'e-frames,  being  a  cheaper  method  than  carving,  by  nearly 
bJ  per  cent.  It  is  made  as  folJows  :  2  pounds  best  whiting, 
1  pound  glue,  and  J  pound  Unseed  oil  are  heated  together,  t^e 
comijosiiion  being  continually  stirred  until  the  ditierent  sub- 
stances are  thoroughly  incorporated.  Let  the  compound  cool, 
and  then  lay  it  on  a  stone  covered  with  powdered  whiting, 
and  heat  it  well  until  it  becomes  of  a  tough  and  firm  consistence. 
It  may  then  be  put  by  for  use,  covered  with  wet  cloths  to  keep  it 
fresh.  When  wanted  for  use  it  must  be  cut  into  pieces  adapted 
to  the  size  of  the  mould,  into  which  it  is  forced  bj'  a  screw  press. 
The  ornament,  or  cornice,  is  fixed  to  the  frame  or  wall  with  glue, 
or  with  white  lead. 

Coavfte  Stuff  for  Plasterinf/.—Cnavae  stuff,  or  lime  and 
hair,  as  it  is  sometimes  called,  is  prepared  in  the  same  way  as 
common  n.ortar,  with  the  addition  of  hair  procured  from  the 
tanner,  which  must  be  well  mixed  with  the  mortar  by  means  of 
a  three-pronged  rake,  until  the  hair  is  equally  distributed 
throughout  the  comp.osition.  The  mortar  should  be  first  form- 
ed, and  when  the  lime  and  sand  have  been  thoroughly  mixed, 
the  hair  should  be  added  bj^  degrees,  and  the  whole  so  thorough- 
ly united  that  the  hair  shall  appear  to  be  equally  distributed 
throughout. 

Concrete. — A  compact  mass,  composed  of  pebbles,  lime,  and 
sand,  employed  in  the  foundations  of  buildings.  The  best  pro- 
portions are  60  parts  of  coarse  pebbles,  25  of  rough  sand,  and  15 
of  lime:  others  recommend  bO  jsarts  pebbles,  40  parts  river  sand, 
and  only  10  parts  lime.  The  pebbles  should  not  exceed  about 
|-  pound  each  in  weight.  Abbe  Moigno,  in  his  valuable  scientific 
journal,  "Les  Mondes,"  relates  his  personal  experience  with  a 
concrete  formed  of  fine  wrought  and  cast  iron  filings  and  Port- 
land cement.  The  Abbe  states  that  a  cement  made  thus  is  hard 
enough  to  resist  any  attempts  to  fracture  it.  As  he  states  that 
the  iron  filings  are  to  replace  the  sand  usually  put  into  the  mix- 
ture, we  presume  that  the  relative  quantities  are  to  be  similar. 

Concrete  Floors  and  Walha. — Compost  for  barn  and 
kitchen  floors  :  After  the  ground  on  which  the  floor  is  intended 
to  be  made  is  levelled,  let  it  be  covered  to  the  thieknesj  of  3  or  4 
inches  with  stones,  broken  small,  and  well  rammed  down  ;  upon 
which  let  there  be  rtin,  about  \h  inches  above  the  stones,  1  part 
by  measure  calcined  ferruginous  marl,  and  2  parts  coarse  sand 
and  fine  gi-avel,  mixed  to  a  thin  consistence  with  water.  Before 
this  coating  has  become  thoroughly  set,  lay  upon  it  a  coat  of  cal- 
cined marl,  mixed  with  an  equal  part  of  fine  sand,  1  to  liV  inches 
thick,  levelled  to  an  even  surface.  The  addition  of  blood  will 
render  this  compost  harder. 


26-1  PRACTICAL   MECHANICAL   RECEIPTS. 

Rotnan  Cement. — Calcine  3  parts  of  any  ordinary  clay, 
and  mix  it  witia  2  parts  lime ;  grind  it  to  powder,  and  calciuo 
again.  This  makes  a  beautiful  cement,  improjierly  called  lloman, 
since  the  preparation  was  entirely  iinknown  to  the  Romans. 

Gd^ige  Stuff. — This  is  chiefly  used  for  mouldings  and  cor- 
nices which  are  run  or  formed  with  a  wooden  mould.  It  consists 
of  about  1-5  plaster  of  Paris,  mixed  gradually  with  4-5  line  stuflf. 
When  the  work  is  reqxiired  to  set  very  expeditiously,  the  propor- 
tion of  plaster  of  Paris  is  increased.  It  is  often  necessary  that 
the  plaster  to  be  used  should  have  the  property  of  setting  imme- 
diately it  is  laid  on,  and  in  all  such  cases  gauge  stuff  is  used,  and 
consequently  it  is  extensively  employed  for  cementing  ornaments 
to  walls  or  ceilings,  as  well  as  for  casting  the  ornaments  them- 
selves. 

To  Lacquer  Bt-a.-^n-lforJc—lt  the  work  is  old,  clean  it 
first,  according  to  the  directions  hereafter  given  ;  but  if  new,  it 
will  merely  re(iuire  to  be  freed  from  dust,  and  rubbed  with  a 
piece  of  wash-leather,  to  make  it  as  bright  as  possible.  Putthe 
work  on  a  hot  iron  plate  (or  upon  the  top  of  tlie  stove),  till  it  is 
moderately  heated,  but  not  too  hot,  or  it  will  Idistcr  the  lacquer: 
then,  according  to  the  color  desired,  take  of  the  f;)l!owing  prepar 
rations,  and,  making  it  warm,  lay  hold  of  the  work  with  a  piiir 
of  pincers  or  pliers,  and  with  a  soft  brush  apply  the  lacquer, 
being  careful  not  to  rub  it  on,  but  stroke  the  brush  gently  one 
way,  and  ]  lace  the  work  on  the  hot  plate  again  till  the  vanii;h  is 
hard  ;  but  do  not  let  it  remain  too  long.  Experience  will  best 
tell  you  when  it  shoiild  be  removed.  Some,  indeed,  do  not  place 
it  on  the  stove  or  plate  a  second  time.  If  it  should  not  be  (jnito 
covered,  you  may  repeat  it  carefully;  and,  if  pains  be  taken  v/ith 
the  lacquer,  it  w'ill  look  etjual  to  metal  gilt. 

To  clean  old  Bra.ss-lf'otJc  for  Lacqiieriut/.—Malie 

a  strong  lye  of  wood  ashes,  which  may  be  strengthened  by  soa])- 
lees  ;  put  in  the  brass-work,  and  the  lac(pier  will  soon  come  off; 
then  have  ready  a  mixture  of  aquafortis  and  water,  sufficiently 
strong  to  take  off  the  dirt  ;  wasli  it  aft(U-ward  in  clean  water, 
and  laccpicr  it  with  such  of  the  following  compositions  as  may 
be  most  suitable  to  the  work. 

(ilold  Larqner.—Tnt  into  a  clean  four-gallon  tin,  1  pound 
ground  turmeric,  1.',  ounces  jjowdered  gamhoge,  \]}  (umces  iiow- 
dered  gum  sandarach,  3  i)onnd  sli<lla(\  and  'J  gallons  siiints  of 
wine.  After  being  agitated,  dissolved,  and  strained,  add  1  ]iint 
of  turpentine  varnish,  well  mixed. 

Deep  Gold  Jvf/rf/ we/'.  — Seed-lac,  3  ounces  ;  turmeric,  1 
oun(!(S  dragon's  bloo.l,  \  ounce;  alcohol.  1  jint.  Digest  for  n 
week,  frequently  shaking,  decant  an  1  iilt.-r.     Deep  gold  colored. 

J>arh-  <i<d<l-<'olur<d  Lurqiirr.  Strong«!.st  alcohol,  i 
ounces;  Siiiiiiish  aniiotto,  H  gr.iins  ;  jiowdereil  turmeric,  2 
drams  ;  red  sanders,  12  grains.  I.ifnse  and  aiM  sliellac,  etc., 
and  when  .lissolvcl  add  :t:i  drojjs  of  spirits  of  turpiiitiiu!. 


PRACTICAL   MECHANICAL   RECEIPTS.  265 

To  niak.'  Gold  Lacquer  for  ^i'rts.s.— Eectified  spirits 
of  wine,  J  pint ;  mix  ^  pound  of  seed-lac,  picked  clean,  and  clear 
of  all  pieces  (as  upon  that  depends  the  beauty  of  the  lacquer), 
with  the  spirits  of  wine  ;  keep  them  in  a  warm  place,  and  shake 
them  repeatedly.  "When  the  seed-lac  is  quite  dissolved,  it  is  fit 
for  use. 

Gold^Colored  Lacquer  for  Watch-Ketjs,  etc. — Seed- 
lac,  6  ounces  ;  amber,  2  ounces  ;  gamboge,  2  ounces  ;  extract  of 
red  sandal  wood  in  water,  2-i  grains  ;  dragon's  blood,  6J  grains  ; 
oriental  saflron,  3G  grains  ;  jjounded  glass,  4  ounces  ;  pure  alco- 
hol, 36  ounces.  The  seed-lac,  amber,  gamboge,  and  dragon's 
blood  must  be  pounded  very  fine  on  porphyry  or  clean  marble, 
and  mixed  with  the  pounded  glass.  Over  this  mixtiire  is  poured 
the  tincture  ibrmed  by  infusing  the  saffron  and  the  extract  of 
sandal- wood  in  the  alcohol  for  2  J-  hours.  Metal  articles  that  are 
to  be  covered  with  this  varnisli  are  heated,  and,  if  they  are  of  a 
kind  to  admit  of  it,  are  immersed  in  joackets.  The  tint  of  the 
varnish  may  be  varied  in  any  degree  required,  by  altering  the 
proportions  of  the  coloring  quantities  according  to  circum- 
stances. 

Gold  Lacquer. — Groimd  turmeric,  1  pound  ;  gamboge,  1| 
ounces  ;  gum  sandarach,  3^  pounds  ;  shellac,  \  pound  ;  all  in 
powder  ;  rectified  spirits  of  wine,  2  gallons.  Dissolve,  strain, 
and  add  turpentine  varnish,  1  pint. 

Sra^S  Lficquer. — Take  8  ounces  shellac,  2  ounces  sanda- 
rach, 2  ounces  annotto,  \-  ounce  dragon's  blood  resin,  1  gallon  of 
siiirits  of  wine.  The  article  to  be  lacquered  should  be  heated 
slightly,  and  the  lacquer  applied  by  means  of  a  soft  camel's-hair 
brush. 

Lacquer  for  Bronzed  Dipped  Work. — A  lacquer  for 
bronzed  dipped  wor'.c  maj'  be  made  thus  :  Alcohol,  12  gallons  ; 
scod-lac,  9  pounds  ;  turmeric,  1  pound  to  the  gallon  ;  .Spanish 
saffron,  4  ounces.  The  saffron  may  be  omitted  if  the  lacquer  is 
to  be  very  light. 

Lacquer  for  Tin  Plate. — Best  alcohol,  8  ounces;  tur- 
meric, 4  drams  ;  hay  saffron,  2  scrux^les  ;  dragoii's  blood,  4 
scruples  ;  red  sanders,  1  scruple  ;  shellac,  1  ounce  ;  gum  sanda- 
rach, 2  drams  ;  gum  mastic,  2  drams ;  Canada  balsam,  2 
drams  ;  when  dissolved,  add  si^irits  of  turpentine,  80  drops. 

Iron  Lacquer. — Take  12  parts  amber,  12  parts  turpentine, 
2  parts  resin,  2  parts  asphaltum,  6  parts  drying  oil.  Or  :  3 
pounds  asphaltum,  h  pound  shellac,  1  gallon  turpentine. 

Red  Lfccquc r.  —  Tiike  2  gallons  spirits  of  wine,  1  pound 
dragon's  blood,  3  pounds  Spanish  annotto,  4^  pounds  gum 
sandarach,  2  pints  turpentine.     Made  as  pale  brass  lacquer. 

lied  Lacquer. — Spanish  annotto,  3  pounds;  dragon's  blood, 
1  pound  ;  gum  sandarac'a,  3^  pounds  ;  rectified  spirit,  2  gallons  ; 
turpentine  varnish,  1  quart.     Dissolve  and  mix  as  the  last. 

12 


-G6  PRACTICAL   MECHANICAL   RECEIPTS. 

Pale  Till  Lacquer. — Strongest  alcohol,  4  ounces  ;  pow- 
dered turmeric,  2  drams ;  hay  saffron,  1  scru_  le ;  dragon's 
blood  in  powder,  2  scruples  ;  red  sanders,  .}  scruple.  Infuse  this 
mixture  in  the  cold  for  48  hoiirs,  pour  oflf  the  clear,  and  strain 
the  rest ;  then  add  powdered  shellac,  ^  ounce  ;  sandarach,  1 
dram  ;  mastic,  1  dram ;  Canada  balsam,  1  dram.  Dissolve 
this  in  the  cold  by  frequent  agitation,  laying  the  bottle  on  its 
side,  to  present  a  greater  surface  to  the  alcohol.  When  dissolved, 
add  40  drops  of  spirits  of  turpentine. 

Pale  Brass  Lacquer. — Take  2  gallons  spirits  of  wine, 
3  ounces  cape  aloes,  cut  small,  1  pound  line  pale  sliellac,  1  ounce 
gamboge,  cut  small.  Digest  for  a  week,  shake  frequently,  decant 
and  filter. 

To  niahe  Lacquer  of  various  Tints.— Vwt  4  ounces 

best  gum  gamboge  into  32  ounces  spirits  of  turpentine;  4  ounces 
dragon's  blood  into  the  same  quantity  of  spirits  of  turpentine  as 
the  gamboge,  and  1  ounce  annotto  into  8  ounces  of  the  same 
spirits.  The  3  mixtures  should  be  made  in  diflerent  vessels. 
They  shoiild  then  be  kept  for  about  two  weeks  in  a  warm  place, 
and  as  much  exposed  to  the  sun  as  possible.  At  the  end  of  that 
time  they  will  be  fit  for  use  ;  and  any  desired  tints  may  be  ob- 
tained by  making  a  composition  from  them,  with  such  propor- 
tions of  each  liquor  as  the  nature  of  the  color  desired  will  point 
out. 

Diirdhleand  lustrous  Ulach-  Coatiuf/  for  Metals.— 

The  bottom  of  a  cylindrical  iron  pot,  which  should  be  about  18 
inches  in  height,  is  covered  half  an  inch  with  jjowdered  bitu- 
minous coal ;  a  grate  is  then  put  in  and  tlie  pot  tilled  with  the 
articles  to  be  varnished.  Articles  of  cast  iron,  iron  wire,  brass, 
zinc,  steel,  tinned  iron,  «!tc.,  may  be  subjected  to  the  same  treat- 
ment. The  cover  is  then  put  on  and  the  pot  heated  over  a  coke 
fire  under  a  wtll-drawing  chimnoy.  In  the  beginning  the  mois- 
ture only  evaporat(!S,  but  soon  the  coking  commences,  and  deep 
brown  vapors  escape,  which  irritate  the  throat.  When  the  bot- 
tom of  the  i)ot  lias  been  lieated  for  15  minutes  to  a  dull  red  lient, 
the  coal  has  been  mostly  converted  into  cokti  ;  the  ]>ot  is  then 
removed  from  the  fire,  and  after  standing  10  minutes  opened  for 
evaporation,  all  tlie  articles  will  bo  found  covered  with  tlie  above 
described  coating.  Tiiis  lac(|uer  is  not  only  a  i)rotection  against 
oxidation  of  metals,  but  will  stand  also  a  considerable  heat,  only 
disaiipearing  at  l)eginning  redness,  and  therefore  its  useful  ap- 

t)li(;aiion  for  ovens  and  T\irnactts.  The  coating  ])roduced  is  thin, 
ustrous,  and  cannot  easily  be  scratched.  Fine  iron-ware  arti- 
cles, such  as  sieves,  are  in  this  manner  coated  with  remarkable 
evenness,  which  cannot  be  accom])lished  in  anv  other  way. 
Articles  made  of  tin,  or  soldered,  cannot  bo  subjected  to  this 
process,  as  they  would  fuse.  Snndler  articles,  like  hooks  and 
eves,  r(^c(!iv(!  this  coating  l)y  heating  tliein  togetlier  with  small 
pieces  of  bituminous  coal  in  a  cylindrical  sheet  iron  drum  like 
t'.uit  used  for  roasting  coUee,  until  they  present  the  desired  lus- 
trous black  ap])earance. 


PRACTICAL   MECHAXICAL   RECEIPTS.  267 

Lacquer  for  Philosophical  Instriiinents. — Gamboge, 
1^  ounces  ;  gum  sandaracli,  4  ounces  ;  gum  elemi,  4  ounces  ; 
best  dragon's  blood,  2  ounces  ;  terra  merita,  IJ  ounces  ;  oriental 
saflfron,  4  grains  ;  seed-lac,  2  ounces  ;  pounded  glass,  6  ounces  ; 
pure  alcohol,  40  ounces.  The  dragon's  blood,  gum  elemi,  seed- 
lac,  and  gamboge,  are  all  pounded  and  mixed  with  the  glass. 
Over  them  is  jioured  the  tincture  obtained  by  infusing  the  saifron 
and  terra  merita  in  the  alcohol  for  24  hours.  This  tincture, 
before  being  poured  over  the  dragon's  blood,  etc.,  should  be 
strained  through  a  piece  of  clean  linen  cloth,  and  strongly 
squeezed.  If  the  dragon's  blood  gives  too  high  a  color,  the  quan- 
tity may  be  lessened  according  to  circumstances.  The  same  is 
the  case  with  the  other  coloring  matters.  In  choosing  the  terra 
merita,  select  that  which  is  sound  and  comiiact.  This  lacquer 
has  a  very  good  effect  when  applied  to  many  cast  or  moulded 
articles  used  in  ornamenting  furniture,  the  irregularity  of  sur- 
face of  which  would  render  it  difficult,  if  not  impossible,  to  pol- 
ish in  the  ordinary  manner. 

To  frost  AUnniniltn. — The  metal  is  plunged  into  a  solu- 
tion of  caustic  potash.  The  surface,  becoming  frosted,  does  not 
tarnish  on  exposure  to  the  air. 

JPlatiim  HI— also  called  platina— is  the  heaviest  substance 
but  one  known,  having  a  sijecific  gravity  of  fully  21,  which  may 
be  raised  to  about  21.5  by  hammering.  It  is  whiter  than  iron, 
harder  than  silver,  infusible  in  the  hottest  furnace,  and  melts 
only  before  the  compound  blow-j^ipe  at  a  heat  of  about  3080°  Fahr. 
On  this  account  it  is  valuable  for  making  capsules,  &c.,  intended 
to  resist  strong  heat.  Platinum  undergoes  no  change  by  ex- 
posure to  air  and  moisture,  or  the  strongest  heat  of  a  smith's 
forge,  and  is  not  attacked  by  any  of  the  pure  acids,  but  is  dis- 
solved by  chlorine  and  nitro-muriatic  acid  (aqua  regia),  though 
with  more  difficulty  than  gold.  Spongy  and  powdered  platinum 
possess  the  remai'kable  property  of  causing  the  union  of  oxygen 
and  hydrogen  gases.  It  is  chiefly  imported  from  South  America, 
but  is  also  found  in  the  Ural  SIountaLns  of  Eussia,  in  Cej'lon, 
and  a  few  other  places.  Platinum,  when  alloyed  with  silver,  is 
soluble  in  nitric  acid  ;  the  pure  metal  is  dissolved  by  aqua  regia, 
and  is  more  or  less  attacked  by  caustic  alkali,  nitre,  phosi^horus, 
&c.,  with  heat.  Platinum  is  preciijitated  from  its  solutions  by 
deoxidizing  substances  under  the  form  of  a  black  powder,  whicli 
has  the  power  of  absorbing  oxygen,  and  again  imparting  it  to 
combustible  substances,  and  thus  cav^sing  their  oxidation.  In 
this  way  alcohol  and  pyroxilic  spirit  may\)e  converted  into  acetic 
and  formic  acids,  etc. 

To  estiituite  the  JPiirit!/  of  Antimony. — Treat  pulver- 
ized antimony  witli  nitric  acid  ;  this  oxidizes  the  antimony,  and 
leaves  it  in  an  insoluble  state,  whilst  it  dissolves  the  other  metals. 
Collect  the  oxide  on  a  filter,  wash,  dry,  ignite,  and  weigh  it. 
This  weight,  multiplied  by  .843  gives  the  weight  of  pure  metal 
in  the  sample  examined.  If  this  has  been  previously  weighed, 
tha  percentage  cf  puio  metal  is  easily  arrived  at. 


268  PRACTICAL   MECHANICAL  RECEIPTS. 

To  jyiirifi/  JPlatiniini. — The  native  alloy  (crude  platinum) 
is  acted  upon,  as  far  as  possible,  with  nitro-muriatic  acid,  con, 
taining  an  excess  of  muriatic  acid,  and  slightly  dihited  witli 
water.  The  solution  is  precipitated  by  the  addition  of  sal-am> 
moniac,  which  throws  down  nearly  the  whole  of  the  platinum 
in  the  state  of  an  ammonio-chloride,  which  is  washed  with  q 
little  cold  water ,  dried,  and  heated  to  redness ;  the  product  ig 
spongy  metallic  platinum.  This  is  made  into  a  thin  uniform 
paste  with  water,  pressed  in  a  brass  mould,  to  squeeze  oiat  the 
water  and  render  the  mass  sufficiently  solid  to  bear  handling. 
It  is  then  dried,  carefully  heated  to  whiteness,  and  hammered 
or  jiressed  in  the  heated  state  ;  after  this  treatment  it  may  be 
rolled  into  plates  or  worked  into  any  desired  shape. 

Phithidteil  Asbestos. — Dip  asbestos  in  a  solution  of 
chloride  of  platinum,  and  heat  it  to  redness.  It  causes  the  in- 
flammation of  hydrogen  in  the  same  manner  as  spongy  platinum. 

Platinum-Black.  Platina  Jlolir. — This  is  platinum 
in  a  finely  divided  state,  and  is  obtained  thus:  Add  to  a  solu- 
tion of  bichloride  of  platinum,  an  excess  of  carbonate  of  soda, 
and  a  qiiantity  of  sugar.  Boil  until  the  precipitate  which  forms 
becomes,  after  a  little  while,  perfectly  black,  and  the  sui)erna- 
tant  liquid  colorli;ss  ;  filter  the  powder, 'wash,  anddrj'itbya 
gentle  heat.  Another  method  is  by  melting  platina  ore  with 
twice  its  weight  of  zinc,  powdering,  digesting  first  in  dihate  sul- 
phuric acid,  and  next  in  dilute  nitric  acid,  to  remove  the  zinc, 
assisting  the  action  of  the  menstruum  by  heat;  it  is  then  digest- 
ed ill  potash  lye,  and  lastly  in  pure  water,  after  which  it  is  care- 
fully dried.  Platinum-black  possesses  the  projierty  of  condens- 
ing gases,  more  especially  oxygen,  into  its  i^ores,  and  afterward 
yielding  it  to  varioxis  oxidizable  substances.  If  some  of  it  be 
mixed  with  alcohol  into  a  paste,  and  spread  on  a  watch  glass, 
pure  acetic  acid  is  given  off,  and  affords  a  ready  means  of  diffus- 
ing the  odor  of  vinegar  in  an  apartment. 

Testa  for  Antinnmif. — An  acid  solution  of  antimony  gives, 
in  combinatinn  witli  sulj)hureted  hydrogen,  an  orange-red  pre- 
ci2)italc,  sparingly  soluble  in  ammonia,  but  readily  solu])le  in 
pure  potassa  and  alkaline  sulpliurcts.  Ilydrosulpliuret  of  am- 
monia throws  down  from  the  aci  1  solution  an  orangr-red  pre- 
cipitate, readily  soluble  in  excess  of  the  i)recipitant,  if  the  latter 
contain  sulphur  in  excess;  and  the  licpior  containing  the  rc-dis- 
Bolv(;d  i)recipitato  gives  a  yellow  or  orange-yellow  i)recipitate  on 
the  addition  of  an  acid.  Ammonia,  and  ])otassa,  and  their  car- 
bonat(!S  (except  in  solutions  of  tartar  emetic)  give  a  bulky  white 
precipitate;  tliat  from  ammonia  bfing  insoluble  in  excess  of  the 
precipitant ;  that  from  ])otassa  readily  so;  while  those  from  the 
carbonate  are  only  soluble  on  tlio  application  of  heat. 

T'o  ohfain  Connmrrial  ^i ntinionif.  Yniw  together  KM) 
jiarts  siili)liunt  of  antimony,  -ID  jiarts  metallic  inui,  and  10  ]>art8 
flry  crude  Kulpliatd  of  soda.  Tiiis  jiroducs  from  (iO  to  Ci  parts 
of  antimony,  besides  the  scorim  or  ash,  which  is  also  valuable. 


PRACTICAL    MECHANICAL   RECEIPTS.  269 

Spoiigij  Platinnni — Dissolve  sejiarately  crude  bichloride 
of  platinum,  and  hydrochlorate  of  ammonia  in  proof  spirit;  add 
the  one  solution  to  the  other  as  long  as  a  precipitate  falls;  this  is 
collected,  and,  while  still  moist,  formed  into  little  balls  or  pieces, 
■which  are  then  dried,  and  gradually  heated  to  redness. 

Sponfjy  Platinum. — Dissolve  platinum,  by  the  aid  of  heat, 
in  a  mixture  of  3  parts  nitric  and  5  parts  muriatic  acid,  avoiding 
great  excess  of  acid.  To  this  solution  add  a  strong  solution  of 
muriate  of  ammonia;  collect  the  resiilting  i:)recipitate  on  a  filter, 
and,  when  nearly  dry,  form  it  into  a  mass  of  the  shape  desired  for 
the  siDonge.  Heat  this  to  whiteness  on  charcoal,  with  a  blow- 
pipe or  otherwise,  and  the  platinum  remains  in  the  spongy  state. 
Its  characteristic  properties  may  be  restored,  when  lost,  by 
simply  heating  it  to  redness. 

To  purify  BifuniifJi. — Dissolve  crude  bismuth  in  nitric 
acid,  and  concentrate  the  solution  by  evaporation.  Then  pour 
the  clear  solution  into  a  large  bulk  of  distilled  water,  and  a 
white  powder  (sub-nitrate  of  bismuth)  will  be  precipitated.  Col- 
lect the  precipitate  and  digest  it  for  a  time  in  a  little  caustic 
potash,  to  dissolve  away  any  arsenious  acid  that  may  be  present; 
next  wash  and  dry  the  sub-nitrate;  heat  it  with  about  one-tenth 
its  weight  of  charcoal  in  an  earthen  crucible,  and  the  pure  bis- 
muth will  be  found  at  the  bottom  of  the  crucible. 

To  separate  maiiiuth  front,  Lead. — Dissolve  the  mixed 
metal  in  nitric  acid;  add  caustic  potash  in  excess,  and  the  oxides 
of  bismuth  and  lead  will  be  preciiDitated,  but  the  lead  oxide  will 
be  at  once  re-dissolved  by  the  alkali.  The  oxide  of  bismuth  can 
then  be  separated  by  filtration,  washed,  and  ignited. 

To  obtain  3IetaUic  Antimony. — Mix  together  16  parts 
Bulphviret  of  antimony  and  6  parts  cream  of  tartar,  both  in  pow- 
der; put  the  mixture,  in  small  quantities  at  a  time,  into  a  vessel 
heated  to  redness  ;  when  reaction  ceases,  fuse  the  mass,  and, 
after  1-5  minutes,  pour  it  out  and  separate  the  metal  from  the 
slag.     The  product  is  nearly  pure. 

Or  :  Equal  parts  of  protoxide  of  antimony  and  bitartrate  of 
potassa  (cream  of  tartar) ;  mix  and  fuse  as  above,  and  poiir  the 
metal  into  small  conical  mov;lds. 

Or:  8  parts  sulphuret  of  antimony,  6  parts  cream  of  tartar,  and 
3  parts  nitre.     Treated  as  above. 

'Or:  2  i^arts  sulphuret  of  antimony  and  1  part  iron  filings;  cal- 
cine at  a  strong  heat  in  a  covered  crucible. 

Black  Uronzes.  —A  very  dark  colored  bronze  may  be  ob- 
tained by  using  a  little  sulphureted  alkali  (sulphuret  of  ammo- 
nia is  best).  The  face  of  the  medal  is  washed  over  with  the  solu- 
tion, which  should  be  dilute,  and  the  medal  dried  at  a  gentle 
heat,  and  afterward  polished  with  a  hard  hair  brush.  Sulphu- 
reted hydrogen  gas  is  sometimes  employed  to  give  this  black 
bronze,  but  the  efifect  of  it  is  not  so  good,  and  the  gas  is  very 
deleterioiis  when  breathed.  In  these  bronzes  the  surlace  of  the 
copper  is  converted  into  a  sulphuret. 


270  PRACTICAL   MECHANICAL   RECEIPTS. 

NageVs  Method  of  Elect t'o plating  irith  Nickel. — 

A  process  devised  by  Mr.  Nagel,  of  Hamburg,  for  coating  iron, 
steel,  and  other  oxidizable  metals  with  an  electro-deposit  of 
nickel  or  cobalt,  consists  in  taking  4  parts,  by  weight,  of  pure 
sulphate  of  the  protoxide  of  nickel  by  crystallization,  and  2 
parts,  by  weight,  of  pure  ammonia,  so  as  to  form  a  doiible  salt, 
which  is  then  dissolved  in  60  parts  of  distilled  water,  and  12 
parts  of  ammoniacal  solution  of  the  sjiecific  gravity  of  .909  added. 
The  electro-deposit  is  effected  by  an  ordinary  galvanic  current, 
using  a  platiniim  positive  pole,  the  solution  being  heated  to 
about  lOO'^  Fahr.  The  strength  of  the  galvanic  current  is  regii- 
lated  according  to  the  number  of  objects  to  be  coated. 

Antique  Brotize  Coloring. — To  impart  a  brass  or  an- 
tique bronze  color,  either  of  the  three  following  means  may  be 
adopted  :  A  solution  of  copper,  with  some  acetic  acid.  Or  :  The 
means  before  described  for  copi^er  color,  with  a  large  proportion 
of  liquid  ammonia.  Or  :  Water  acidulated  with  nitric  acid,  by 
which  beautiful  bluish  shades  may  be  produced.  It  must  be 
observed,  however,  this  last  process  can  only  be  properly  em- 
ployed on  the  alloys  which  contain  a  jiortion  of  copper. 

To  pi'ep((re  a  JJrass  Solution. — For  each  gallon  of 
water  used  to  make  the  solution,  take  1  part  carbonate  of  ammo- 
nia, 1  pound  cyanide  of  potassium,  2  ounces  cyanide  of  cojiper, 
and  1  ounce  cyanide  of  zinc.  This  constitutes  the  solution  for 
the  decomi)osing  cell.  It  may  bo  prepared,  also  from  the  above 
proportions  of  carbonate  of  ammonia  and  cyanide  of  potassium, 
by  immersing  in  it  a  large  sheet  of  brass  of  the  desired  quality, 
and  making  it  the  anode  or  positive  electrode  of  a  i)Owerful 
galvanic  battery  or  magneto-electric  machine  ;  and  making  a 
small  piece  of  metal  the  cathode  or  negative  electrode,  from 
which  hydrogen  must  be  freely  evolved.  This  ojicration  is  con- 
tinued till  the  solution  has  taken  up  a  sufficient  quantity  of  the 
brass  to  produce  a  regulino  deposit. 

To  electroplate  ■ivith  JBrass. — For  wrought  or  fancy 
work,  about  15u"  Fahr.  will  give  excellent  results.  The  galvanic 
battery,  or  magneto-electric  jnachine,  must  be  capabhi  of  evolv- 
ing hydrogen  Irccily  from  the  cathode  or  negative  electrode,  or 
article  attached  thereto.  It  is  preferred  to  have  a  largo  anode  or 
l)ositivo  electrode,  as  this  favors  the  evolution  of  hydrogen. 
The  article  or  articles  treated  as  before  described  will  immediate- 
ly become  coated  with  brass.  By  continuing  the  process,  any 
desired  thickness  may  be  oljtaincd.  Should  the  coi)j)('r  have  a 
tendency  to  come  down  in  a  greater  proportion  than  is  desired, 
which  may  ])e  known  by  the  deposit  assuming  too  red  an  ap- 
pearanct^  it  is  corrected  bv  the  addition  of  carljonate  of  ammo- 
nia, or  by  ft  rciduction  of  temp(!rature  when  tin;  solution  is 
heitful.  Should  tlie  zinc  have  a  tendency  to  come  down  in  too 
great  a  proportion,  wliich  may  be  seen  l)y  the  dejxjsit  being  too 
])ale  in  its  a|)|)eiiniiHM!,  this  is  competed  by  the  addition  of  cya- 
nide of  liotassium  or  by  aa  iucreaso  of  tomiJcrature. 


PRACTICAL   MECHANICAL   RECEIPTS.  271 

To  protect  Steel  from  rusting. — It  has  been  found  by 
experiment  that  an  electro-deposited  coating  of  nickel  protects 
the  surface  of  polished  steel  completely  from  rust.  Swords, 
knives,  and  other  articles  of  steel  liable  to  exposure,  may  be 
coated  with  nickel  without  materially  altering  the  color  of  the 
metal. 

To  electro  [date  with  Qervian  Silver. — The  alloy, 
German  silver,  is  deposited  by  means  of  a  solution  consisting  of 
carbonate  of  ammonia  and  cyanide  of  potassium  (in  the  propor- 
tions given  above  for  the  brass),  and  cyanides  or  other  com- 
pounds of  nickel,  cojiper,  and  zinc,  in  the  requisite  proportions 
to  constitute  German  silver.  If  is,  however,  preferred  to  make 
the  solution  by  means  of  the  galvanic  battery  or  magneto-electric 
machine,  as  above  described  for  brass.  Should  the  copper  of  the 
German  silver  come  down  in  too  great  a  proportion,  this  is  cor- 
rected by  adding  carbonate  of  ammonia,  which  brings  down  the 
zinc  more  freely  ;  and  should  it  be  necessary  to  bring  down  the 
copper  in  greater  quantity,  cyanide  of  potassium  is  added — such 
treatment  being  similar  to  that  of  the  brass  before  described. 

Brown  Bronzes  for  Medals,  <Cc. — Take  a  wine-glass  of 
water,  and  add  to  it  4  or  5  drops  nitric  acid  ;  with  this  solution 
wet  the  medal  (which  ought  to  have  been  previously  well  cleaned 
from  oil  or  grease)  and  then  allow  it  to  dry;  when  dry  impart  to 
it  a  gradual  and  equable  heat,  by  which  the  surface  will  be  dark- 
ened in  proportion  to  the  heat  applied. 

CJiinese  Bronze. — Take  2  ounces  each  verdigris  and  ver- 
milion ;  5  ounces  each  alum  and  sal-ammoniac,  all  in  fine  pow- 
der, and  sufficient  vinegar  to  make  a  paste  ;  then  spread  it  over 
the  surface  of  the  copjier,  jDreviously  well  cleaned  and  bright- 
ened ;  uniformly  warm  the  article  by  the  fire,  and  afterward 
well  wash  and  dry  it,  when,  if  the  tint  be  not  deep  enough,  the 
process  may  be  repeated.  The  addition  of  a  little  sulphate  of 
copper  inclines  the  color  to  a  chestnut  brown;  and  a  little  borax 
to  a  yellowish  brown.  Much  employed  by  the  Chinese  for  cop- 
per tea-ums. 

German  3Iethod  of  bronzing  Brass  black. — There 
are  two  methods  of  procuring  a  black  lacqiier  upon  the  surface 
of  brass.  The  one,  which  is  that  usually  employed  for  optical 
and  scientific  instruments,  consists  in  first  iiolishing  the  object 
with  tripoli,  then  washing  it  with  a  mixture  composed  of  1  part 
nitrate  of  tin  and  2  parts  chloride  of  gold,  and,  after  allowing 
this  wash  to  remain  on  for  about  12  or  15  minutes,  wiping  it  off 
Avith  a  linen  cloth.  An  excess  of  acid  increases  the  intensity  of 
the  tint.  In  the  other  method,  copper  turnings  are  dissolved  in 
nitric  acid  until  the  acid  is  satiirated  ;  the  objects  are  immersed 
in  the  solution,  cleaned,  and  subsequently  heated  moderately 
over  a  charcoal  fire.  This  process  must  be  repeated  in  order  to 
produce  a  black  color,  as  the  first  trial  only  gives  a  deep  green  ; 
when  the  desired  color  is  attained,  the  finishing  touch  is  given 
by  polishing  with  olive  oil. 


272  rBACTICAL   MECHANICAL   RECEIPTS. 

BUlclc  Bronzes  — Many  metallic  solutions,  such  as  weak 
acid  solutions  of  platinum,  gold,  palladium,  antimony,  etc.,  will 
impart  a  dark  color  to  the  surface  of  medals  when  they  are  dip- 
ped into  them.  The  medal,  after  bcin;^  dijiped  into  the  metallic 
solution,  is  to  be  well  washed  and  brushed.  In  such  l)ronzes  the 
metals  contained  in  the  solution  are  iirccii^itated  upon  the  face 
of  the  copprr  medal,  which  effect  is  accompanied  by  a  jiartial 
solution  of  the  copper. 

Xagel's  Method  of  Elertrophitiug  Metal  with  Co- 
halt. — For  coating  with  cobalt,  1:J8  parts,  by  weight,  of  pure 
sulphate  of  cobalt,  are  combined  with  60  parts  of  pr.ro  ammonia, 
to  form  a  double  salt,  which  is  tjacn  dissolved  in  1,00 J  parts  of 
distilled  water,  and  120  parts  of  ammoniacal  solution,  of  the 
same  si^ecific  gravity  as  before,  are  added.  The  jirocess  of  depo- 
sition with  cobalt  is  the  same  as  with  nickel. 

To  malce  jBronze  Poirder  for  Plaster  Cftsts,  <Cr. — 
To  a  solution  of  soda-soap  in  linseed  oil,  cleared  by  straining, 
add  a  mixture  of  4  pints  sulphate  of  copper  solution,  and  1  pint 
sulphate  of  iron  solution,  which  precipitates  a  metallic  soap  of  a 
peculiar  bronze  hue ;  wash  with  col  1  water,  strain,  and  dry  to 
powder. 

To  bronze  Plaster  Casts,  <f7'. — The  powdered  soap  of 
the  last  receipt  is  tlius  applied  :  lloil  3  i)ounds  pure  linseed  oil 
with  12  ounces  finely  powdere  1  litharge;  strain  through  a  coarse 
canvas  cloth,  and  allow  to  stanil  until  clear  ;  15  ounces  of  this 
soap  varnish,  mixed  with  12  ounces  metallic-soap  jjowder  (see 
last  receipt),  and  5  ounces  fine  white  wax,  are  to  bo  melted  to- 
gether at  a  gentle  heat  in  a  porcelain  basin,  by  means  of  a  water- 
bath,  and  allowed  to  remain  for  a  time  in  a  melted  state  to  expel 
any  moisture  that  it  may  contain  ;  it  is  theu  applied  with  a 
brush  to  the  surface  of  the  plaster  previously  heated  to  200"" 
Fahr.,  being  careful  to  lay  it  on  smoothly,  and  without  filling  up 
any  small  indentations  of  the  plaster  design.  Place  it  for  a  few 
days  in  a  cool  place  ;  and,  as  soon  as  the  smell  of  the  soap  Aar- 
nish  has  gone  oft",  rub  the  svirface  over  with  cotton  wool,  or  fine 
linen  rag,  and  varicigated  with  a  few  streaks  of  metal  powder  or 
shell  gold.  Small  objects  may  be  dipped  in  the  melted  mixture, 
and  exposed  to  the  heat  of  a  fire  till  thoroughly  penetrated  and 
evenly  coated  with  it. 

To  viahe  lironzing  for  U'ood.—iWmA  separately  to  a 
fint!  powder.  Prussian  blue,  clirome  yellow,  raw  umher,  lamp- 
black, and  clay,  and  mix  in  sut^h  jjroportions  as  will  produce  a 
desired  dark  green  hue  ;  tlien  mix  with  moderately  stroiig  glue 
size. 

To  bronze  WO')il  — l-irst  coat  the  clean  wood  with  a  mix- 
ture of  si/e  and  laiuj)-black  ;  then  apply  two  coats  of  the  green 
colored  sizing  in  the  List  reecipt,  and  lastly  with  bninz(!  powder, 
such  as  j)owd<'ri-d  l)ut(Oi  foil,  mosaic  gold,  .Vc,  laid  on  with  a 
brush.  Pinish  with  a  thin  solution  of  castilo  soap  ;  and,  when 
dry,  rub  with  a  soft  woolen  cloth. 


|0 


PRACTICAL   MECHANICAL   EECEIPTS.  273 

Bronzintf  with  Crocus. — Make  a  thin  paste  of  crocus  and 
water  ;  lay  this  i>aste  on  the  face  of  the  medal,  which  must  then 
be  put  into  an  oven,  or  laid  on  an  iron  jDlate  over  a  slow  fire  ; 
when  the  paste  is  perfectly  reduced  to  jjowder,  brush  it  off  and 
lay  on  another  coating' ;  at  the  same  time  quicken  the  fire,  tak- 
ing care  that  the  additional  heat  is  uniform  ;  as  soon  as  the  sec- 
ond a^jplication  of  paste  is  thoroughly  dried,  briish  it  off.  The 
medal  being  now  effectually  secured  from  grease,  which  often 
occasions  failures  in  bronzing,  coat  it  a  third  time,  but  add  to 
the  strength  of  the  fire,  and  sustain  the  heat  for  a  considerable 
time  ;  a  little  experience  will  soon  enable  the  operator  to  decide 
when  the  medal  may  be  withdrawn  ;  the  third  coating  being 
removed,  the  surface  will  present  a  beautiful  brown  bronze.  If 
the  bronze  is  deemed  too  light  the  process  can  be  repeated. 

To  bronze  Porcelain,  Stoneware,  and  Composition 
Picture- Frames. — A  bronzing  process,  applicable  to  porce- 
lain, stoneware,  and  composition  picture  and  looking-glass 
frames,  is  performed  as  follows  :  The  articles  are  first  done  over 
with  a  thin  solution  of  water-glass  by  the  aid  of  a  soft  brush. 
Bronze  powder  is  then  dusted  on,  and  any  excess  not  adherent 
is  knocked  off  by  a  few  gentle  taps.  The  article  is  next  heated, 
to  dry  the  silicate,  and  the  bronze  becomes  firmlj'  attached. 
Probably,  in  the  case  of  porcelain,  biscuit,  or  stoneware,  some 
chemical  union  of  the  silicate  will  take  place,  but  in  other  cases 
the  water-glass  will  only  tend  to  make  the  bronze  powder  adhere 
to  the  surface.  After  the  heating,  the  bronze  may  be  jjolished  or 
burnished  with  agate  tools. 

Browning  for  Gu)i-I>arrCiS.—^lix  1  ounce  each  aqua- 
fortis and  sweet  spirits  of  nitre  ;  4  ounces  jjowdered  blue  vitriol ; 
2  ounces  tincture  of  iron,  and  water,  1  i  pints  ;  agitate  until  dis- 
solved. 

Or :  Blue  vitriol  and  sweet  sjiirits  of  nitre,  of  each  1  ounce ; 
water,  1  pint ;  dissolve  as  last. 

Or  :  Mix  equal  i)arts  of  butter  of  antimony  and  sweet  oil,  and 
apply  the  mixture  to  the  iron  previously  warmed. 

To  brown  Gun-SarreJs.— The  gun-barrel  to  be  browned 
must  be  first  polished  and  then  rubbed  with  whiting  to  remove 
all  oily  matter.  Its  two  ends  should  be  stopped  with  wooden 
rods,  which  serve  as  handles,  and  the  touch-hole  filled  with  wax. 
Then  rub  on  above  solution  with  a  linen  rag  or  sponge  till  the 
whole  surface  is  equally  moistened.  Let  it  remain  till  the  next 
day,  then  rub  it  off  with  a  stiff  brush.  The  liquid  may  be  again 
applied  until  a  proper  color  is  produced.  When  this  is  the 
case,  wash  in  pearlash  water,  and  afterward  in  clean  water,  and 
then  polish,  either  with  the  burnisher  or  with  bees-wax ;  or 
apply  a  coat  of  shellac  varnish. 

Bclffian  BiirnisJiitif/  Powder. — A  burnishing  powder 
in  use  in  Belgium  is  composed  of  i  pound  fine  chalk,  3  ounces 
pipe  clay,  2  otinces  white  lead,  J  ounce  magnesia  (carbonate), 
and  the  same  quantity  of  jeweller's  rouge, 

12* 


274  PRACTICAL   MECHANICAL   RECEIPTS. 

Drab  Bronze  for  Brciss. — Brass  obtains  a  very  beautiful 
drab  bronze  by  being  worked  in  moulders'  damp  sand  for  a  short' 
time  and  brushed  up. 

To  protect  Silver-Ware  from  tarnishing.— The  loss 
of  silver  which  results  from  the  impregnation  of  our  atmosphere 
with  sulphur  comi)ounds,  especially  where  gas  is  burned,  is  very 
great.  Silversmiths  may  thank  one  of  their  confraternity — ]Mr. 
Strolberger,  of  Munich — for  a  happy  thought.  He  seems  to  have 
tried  various  jilans  to  save  his  silver,  if  possible.  He  covered 
his  goods  with  a  clear  white  varnish,  but  foiind  that  it  soon 
turned  yellow  in  the  window,  and  sjioiled  the  look  of  his  wares. 
Then  he  tried  water-glass  (solution  of  silicate  of  potash),  but  this 
did  not  answer.  He  tried  some  other  solutions,  to  no  purpose  ; 
but  at  last  he  hit  upon  the  expedient  of  coating  his  goods  over 
with  a  thin  coating  of  collodion,  which  he  found  to  answer  per- 
fectly. No  more  loss  of  silver,  and  no  longer  incessant  labor  in 
keeping  it  clean.  The  plan  lie  adopts  is  this  :  He  first  warms  the 
articles  to  be  coated,  and  then  paints  them  over  carefully  with  a 
thinnish  collodion  diluted  with  alcohol,  using  a  wide  soft  brush 
for  the  i)urpose.  Generally,  he  says,  it  is  not  advisable  to  do 
them  over  more  than  once.  Silver  poods,  ho  tells  us,  protected 
in  this  way,  have  been  exposed  in  his  window  more  than  a  year, 
and  are  as  bright  as  ever,  while  others  unprotected  have  become 
perfectly  black  in  a  few  months. 

To   prevent    Coins   and  small   Ornaments  from 

tarnisUiiKJ. — All  ornaments,  whether  gold  or  silver,  can  ^be 
kept  fro  u  tarnishing  if  they  are  carefully  covered  from  the  air  in 
box-wood  sawdust,  which  will  also  dry  them  after  being  washed. 
The  tarnish  on  silver-ware  is  most  often  duo  to  sulphur.  A  gen- 
tleman who  wears  a  silver  watcih  finds  that  it  is  tarnished  from 
the  sulphur  fumes  of  the  rubber  ring  which  holds  together  his 
ferry  tickets.  Sulphur  fumes  enough  get  into  the  air  to  account 
for  all  ordinary  cases  of  tarnishing. 

To  clean  /S'eir^/*.  -Immerse  for  half  an  hour  the  silver  arti- 
cle into  a  solution  made  of  1  gallon  water,  1  jiound  hyposiilphite 
of  soda,  8  ounec!S  niuriiite  of  aiiiinonia,  4  ounces  li(piid  ammonia, 
and  1  ounces  cyanide  of  ])otassium  ;  but,  as  the  latter  substance 
is  poisonous,  it  can  be  dispcmsed  with  if  necessary.  The  article, 
being  taken  out  of  the  solution,  is  washed,  and  rubbed  with  a 
wash-leath(!r. 

To  rlean  Silrer-l*l<fte.— Till  a  largo  Baucei)an  with  water  ; 
))Ut  into  it  1  f)iinee  carbonate  of  ])otasli  anil  .',  pound  whiting. 
Now  i)iit  ill  all  t!u'  spoons,  forlis,  and  small  jilato,  and  boil  them 
for '20  minutes;  after  which  take  the  saucepan  oflf  the  fire  and 
allow  (he  ]i([Uor  to  becomi;  cold  ;  then  take  each  piece  out  and 
jjolish  with  soft  l«!ither.  A  soft  brush  must  bo  used  to  clean  the 
iiiiboHsed  and  engraved  jiarts. 

To  separate  Tin  from  Copper.  -T)i^ost  in  nitric  acid  ; 
the  c'lppir  will  bo  ilissnlvc  1,  but  tlie  tin  will  remain  in  an  io- 
Bolublo  peroxide. 


PRACTICAL   MECHANICAL   RECEIPTS.  275 

Plate  JSoiUng  Powder. — Mix  equal  parts  of  cream  of  tar- 
tar, common  salt,  and  alum.  A  little  of  this  jjowder,  added  to 
the  water  in  which  silver-plate  is  boiled,  gives  to  it  a  silvery 
whiteness. 

Test  for  the  Quant  it  tj  of  Copper  in  a  Conijiound.^ 

The  quantity  of  copper  present  in  any  compound  may  be  esti- 
mated by  throwing  it  down  from  its  solution  by  pure  potassa, 
after  which  it  must  be  carefully  collected,  washed,  dried,  ignited, 
and  weighed.  This  will  give  the  quantity  of  the  oxide  from 
which  its  equivalent  of  metallic  copper  may  be  calculated  ;  every 
5  parts  of  the  former  being  nearly  equal  to  4  of  the  latter  ;  or, 
more  accurately,  every  39.7  parts  are  equal  to  31.7  of  pure 
metallic  copper.  Copper  may  also  be  precipitated  at  once  in  the 
metallic  state,  by  immersing  a  piece  of  polished  steel  into  the 
solution  ;  but  this  method  will  not  give  very  accurate  results. 

To  separate  Lead  from  Copper.— Co\i])ex  may  be  sepa- 
rated from  lead  by  adding  sulphuric  acid  to  the  nitric  solution, 
and  evaporating  to  dryness,  when  water  digested  on  the  re- 
siduum will  dissolve  out  the  sulphate  of  copper,  but  leave  the 
sulphate  of  lead  behind.  From  this  solution  the  oxide  of  copper 
may  be  thrown  down  as  before. 

To  separate  Zinc  from  Co;>per.— Copper  maybe  sepa- 
rated from  zinc  by  sulphuretei  hydrogen,  which  will  throw 
down  a  sulphuret  of  copper,  which  may  be  dissolved  in  nitric 
acid,  and  treated  as  in  last  receipt. 

To  separate  Silver  from  Cojjper.—Bigest,  in  a  state  of 
fiUngs  or  powder,  in  a  solution  of  chloride  of  zinc,  which  dis- 
solves the  copper  and  leaves  the  silver  unchanged. 

To  separate  Copper  from  its  Alloys.— Coyy-pev  may  be 
separated  in  absolute  purity  from  antimony,  arsenic,  bismuth, 
lead,  iron,  &c.,  as  it  exists  in  bell-metal,  brass,  bronze,  and  other 
commercial  alloys,  by  fusin.;,  for  about  half  an  hour,  in  a  cru- 
cible, 10  parts  of  the  metal  with  1  part  each  of  copper  scales 
(black  oxide)  and  bottle  glass.  The  pure  copper  is  found  at  the 
bottom  of  the  crucible,  whilst  the  other  metals  or  impurities  are 
either  volatilized  or  dissolved  in  the  flux. 

Reduction  of  Copper  in  Fine  Powder.— M.  Schiff 
gives  the  following  process  for  obtaining  copper  in  a  state  of  fine 
division :  A  saturated  solution  of  sulphate  of  copper,  together 
with  some  crystals  of  the  salt,  are  introduced  into  a  bottle  or 
flask,  and  agitated  with  some  granulated  zinc.  The  zinc  dis- 
places the  copper  from  its  solution,  fresh  sulphate  dissolving  as 
the  action  goes  on,  until  the  whole  is  exhausted.  Heat  is  disen- 
gaged during  the  operation.  The  vrccipitated  copper  must  be 
washed  and  dried  as  rapidly  as  possible,  to  prevent  oxidation. 

Feather- Sliot  Copper.— Melted  copper,  poured  in  a  small 
stream  into  cold  water.  It  forms  small  pieces,  with  a  feathered 
edge,  hence  the  name.     It  is  used  to  make  solution  of  copper. 


276  PfiACTICAL  MECHANICAL  RECEIPTS. 

Copper  ill  Fine  Powder.— X  solution  of  sulphate  of 
copijer  is  heated  to  the  boiling-point,  and  precipitated  with  sub- 
limated zinc.  The  precipitated  copper  is  then  separated  from 
the  adherent  zinc  b}'  diluted  sulphuric  acid,  and  dried  by  expo- 
sure to  a  moderate  temperature. 

BlaeU  Enamels.— I.  Pure  claj-,  3  parts;  protoxide  of  iron, 
1  part;  mix  and  fuse.     A  line  black. 

n.  Calcined  iron  (protoxide),  12  parts;  oxide  of  cobalt,  1  part; 
mix,  and  add  an  equal  weight  of  white  flux. 

III.  Peroxide  of  manganese,  3  parts;  zaffre,  1  part;  mix  and 
add  it  as  required  to  white  flux.     Zaffre  is  crude  oxide  of  cobalt. 

Blue  Enamels.— I.  Either  of  the  white  fluxes  colored  with 

oxide  of  cobalt. 

IL  Sand,  red-lead,  and  nitre,  of  each  10  jiarts;  flint  glass  or 
ground  flints,  2)  parts;  oxide  of  cobalt,  1  part,  more  or  less,  the 
quantity  depending  on  the  depth  of  color  required. 

Brown  Enumels. — I.  Red-lead  and  calcined  iron,  of  each 
1  part;  antimony,  litharge,  and  sand,  of  each,  2  parts;  mix  and 
add  it  in  any  required  proportion  to  a  flux,  according  to  the 
color  desired.  A  little  oxide  of  cobalt  or  zaffre  is  frequently  add- 
ed, and  alters  the  shade  of  brown. 

II.  Manganese,  5  parts;  red-lead,  16  parts;  flint  powder,  8 
parts;  mix. 

III.  Manganese,  9  parts;  red-lead,  34  parts;  flint  powder,  IG 
parts. 

Green  Etuiniels. — I.  Flux,  2  pounds;  black  oxide  of  cop- 
per, 1  ounce;  red  oxide  of  iron,  \  dram;  mix. 

IL  As  above,  but  use  the  red  oxide  of  coi)per.     Less  decisive. 

IIL  Copper  dust  and  litharge,  of  each  2  ounces;  nitre,  1  oz. ; 
Band,  4  oz. ;  flux,  as  much  as  required. 

IV.  Add  oxide  of  chrome  to  a  sufficient  quantity  of  flux  to  pro- 
duce the  desired  shade;  when  well  managed  the  color  is  superb, 
and  will  stand  a  very  great  heat;  but  in  careless  hands,  it  fre- 
quently turns  on  the  dead-leaf  tinge. 

V.  Transparent  flux,  5  ounces;  black  oxide  of  copper,  2  scru- 
ples; oxide  of  chrome,  2  grains.     Kesembles  the  emerald. 

YI.  Mix  blue  and  yellow  enamel  in  the  required  proportions. 

Orange  Enamels. — I.  Pied-lead,  12  parts;  red  sulphate  of 
iron  and  oxide  of  antimony,  of  each  1  part;  flint  powder,  3  parts; 
calcine,  powder,  and  melt  with  flux,  .00  parts. 

II.  lied-lead,  12  parts;  oxide  of  antimony,  4  parts;  flint  pow- 
der, 3  parts;  red  sulphate  of  iron,  1  part;  calcine,  then  add  flux, 
5  parts  to  every  2  parts  of  this  mixture. 

Jle<l  Enamel.— VnRie  or  flux  colored  with  the  red  or  pro- 
toxide of  cojjper.  Hhould  the  color  jiass  into  the  green  or  brown, 
from  the  partial  peroxidizcraent  of  the  copper,  from  the  heat 
being  raised  too  high,  the  red  color  may  1)0  restored  by  the  addi- 
tion of  any  carVjonaceous  matter,  a.s  tallow,  or  charcoal. 


PRACTICAL   MECHANICAL   RECEIPTS.  277 

JPurjile  Enamels.— 1.  Flux  colored  with  oxiJe  of  gold,  pur- 
p\e  preciiiitate  of  cassius,  or  peroxide  of  manganese. 

II.  Sulphur,  nitre,  vitriol,  antimony,  and  oxide  of  tin,  of  each 
1  jiound;  red-lead,  GO  pounds;  mix  and  fuse,  cool  and  powder; 
add  rose  copper  19  ounces;  zaffre,  1  ounce;  crocus  martis,  U 
ounces;  borax,  3  ounces;  and  1  pound  of  a  compound  formed  ot 
gold,  silver,  and  mercury;  fuse,  stirring  the  melted  mass  with  a 
copper  rod  all  the  time,  then  place  it  m  crucibles,  and  submit 
them  to  the  action  of  a  reverberatory  furnace  for  2i  hours.  This 
is  said  to  be  the  purple  enamel  used  in  the  mosaic  pictures  of  St. 
Peter's  at  Eome. 

OHre  EiKnncis.  Good  blue  enamel,  2  parts;  black  and  yel- 
low enamels,  of  each  1  part;  mix.     (See  Brown  Enamels.) 

Beautiful  lied  Enamel.— The  most  beautiful  and  costly 
red,  inclining  to  the  purple  tinge,  is  produced  by  tinging  glass 
or  Hux  with  the  oxide  or  salts  of  gold,  or  with  the'  purple  j^recip- 
itate  of  cassius,  which  consists  of  gold  and  tin.  In  the  hands  of 
the  skilful  artist,  any  of  these  substances  produces  shades  of  red 
of  the  most  exquisite  hue;  when  most  perfect,  the  enamel  comes 
from  the  tire  quite  colorless,  and  afterward  receives  its  rich  hue 
from  the  flame  of  the  blow-pipe. 

Sose-eolored  Ena uiels.—Puri^le  enamel,  or  its  elements, 
3  parts;  flux,  90  parts;  miv,  and  add  silver-leaf  or  oxide  of  silver, 
1  part  or  less. 

To  make  Solderincf  Fluid  for  Soft  Solder.— Into 
muriatic  acid  put  small  pieces  of  zinc  until  all  bubbling  ceases  ; 
some  add  1  ounce  sal-au\moniac  to  each  pound  of  the  liquid. 

Neutral  Soldering  Fl uid.-Dissolxe  zinc  in  miu-iatic  acid, 
as  above,  then  warm  the  solution  and  add  suflicient  oxide  or 
carbonate  of  tin  in  powder  to  neutralize  it.  This  prevents  the 
fluid  from  corrciing  the  seams. 

Solderincf  i/<//(/df.— Soldering  liquia  is  made  by  taking 
hyilrochloric  acid,  :J^  junt;  granulated  tin,  l.\  ounce;  dissolve  and 
add  some  common  solder  and  hydrochlorate  of  ammonia. 

Flux  for  Solderincf.  —For  common  purposes  powered  resin 
is  generally  used.  Stearic  acid,  obtained  from  the  candle  lacto- 
nes, makes  a  good  flux  for  fine  tin  work. 

Fhi.r  for  solderinr/  Iron  or  Steel.— Dissolve  chloride  of 
zinc  in  alei>hol. 

Flujc  for  solderir.ff  Steel.— This  answers  perfectly  when 
the  fracture  is  an  old  one.  To  a  saturated  solution  of  zinc  in  1 
pint  muriatic  acid,  add  -i  ounces  pulverized  sal-ammoniac  ;  boil 
it  for  ID  minutes;  put  it,  when  cold,  in  a  well-corked  bottle. 
The  boiling  must  be  done  in  a  copper  vessel. 

Flu.r  for  fiolderinff  Pewter.— Ve-vrtev  requires  a  flux  of 
oil,  and  may,  in  addition  to  the  soldering-iron  process,  be  solder- 
ed by  a  current  of  heated  air. 


2T8  PRACTICAL   MSCIIANICAL   RECEIPTS. 

Soft  Soldcring.—The  solder  is  an  alloy  of  2  parts  tin  to  I 
part  lead,  fusible  at  ;J-40°  Fahr. ;  or,  for  cheapness,  the  proportion 
is  sometimes  3  to  2,  fusil. le  at  SI:*-!'.  This  substance  is  applied 
T/ith  a  hot  copper  tool  called  a  soldering-iron,  or  by  blow-pipe 
flame.  H^^^'at,  however,  causes  the  edges  of  the  metal  to  oxidize; 
therefore  the  edges  are  cov^ered  with  a  substance  having  a  strong 
attraction  for  oxygen,  and  disposing  the  metal  to  unite  to  the 
solder  at  a  low  temperature.  Such  substances  are  called  fluxes, 
and  are  chiefly  borax,  resin,  sal-ammoniac,  muriate  of  zinc, 
Venice  turpentine,  tallow,  or  oil. 

Flax  pn'  soUlei'inff  Srass. — For  brass  or  other  similar 
alloy,  resin,  sal-ammoniac,  and  muriate  of  zinc  are  the  projjer 
fluxes.  Should  the  work  be  heavy  and  thick,  the  soldering  re- 
quires to  be  done  over  a  charcoal  Are  in  or<ler  to  keep  the  tool 
heated  within  proper  limits.  It  is  well  to  tin  the  surfaces  before 
soldering  ;  in  some  cases  simjjly  dipping  into  a  pot  of  melted 
solder  effects  the  purpose,  but  tho  dip  must  be  done  instantly  to 
be  efl"ective. 

Flii.1'  for  soldi' rin  f/  ZiHr.  Zinc  in  difficult  to  solder,  from 
the  fact  that  it  is  apt  to  withdraw  the  tin  from  the  soMerixkg  bolt, 
zinc  and  copper  having  a  stronger  atliuity  for  each  other  than  tin 
and  copper.  The  projier  flux  is  muriate  of  zinc,  made  by  dis- 
solving small  bits  of  zinc  or  zinc  drops  in  muriatic  acid  mixed 
with  an  ecpial  bulk  of  water. 

Flitx  for  soldi' rhiff  Tin  and  Lead.— Tin  and  lead  re- 
quire resin  or  oil  as  the  flux. 

Flux   for    soldcrhif/    liriftmnia    HTcfal— Britannia 

metal  should  have  muriate  of  zinc  for  a  flux,  and  be  soldered  by 
the  blow-pipe. 

To  soft  solder  Snifdl  Articles.— -Toin  together  the  parts 
to  be  soldered,  first  moistening  them  with  soldering  fluiil,  lay  a 
small  piece  of  solder  over  the  joint  ami  apply  heat,  eitlur  ovrr  a 
spirit  flame,  or  by  means  of  a  blow-pipe,  as  the  c^ase  may  bo. 
The  heat  should  be  withdrawn  at  the  moment  of  fusion,  other- 
wise the  solder  may  become  brittle.    . 

To  soft  solder  Siiiftoth  Si( rf aces.— Vf hero  two  smooth 
surfaces  are  to  be  joined,  moistiai  the  siirfaces  with  soldering 
fluid,  and  lay  a  piece  of  tin  foil  between  them,  i)ress  them  to- 
get^"^r  closely,  and  ajjply  heat  sufficient  to  fuse  the  tin  foil. 

Hard  Solderimj  or  lira  zing.— The  alloy  used  in  hard 
Roldt-ring  is  generally  made  of  (M|Ual  parts  of  coppcT  and  zinc  ; 
nincli  <it'tii(^  zinc,  howtn'er,  is  lost  in  ihv.  ju'ocess,  so  that  tlit!  real 
l)ri>p(irtioii  is  not  e(pial  jjarts.  The  alloy  is  heated  over  a  char- 
coal fire,  and  brnkfMi  to  granulations  in  an  iron  mortar.  .\  dilfer- 
ent  proportifin  is  used  for  soldering  (topper  and  inui,  viz:  3  zino 
to  1  coppiT.     The  (vuumiircial  name  is  "  spelter  solder." 

Solder  for  Oohl.  Take  12  parts  pure  gold,  2  parta  pure 
silver,  und  2  parts  copper. 


PRACTICAL   MECHANICAL   RECEIPTS.  279 

Flux  for  Spelter  Solder. — The  fliix  employed  for  spelter 
solder  is  borax,  which  can  either  be  used  separatelj',  or  mixed,  by- 
rubbing  to  a  cream,  or  mixed  with  the  solder  in  a  very  little 
water. 

To  UKlhe  Solder. — The  mixture  of  the  metals  is  performed 
by  melting  them  together  in  the  same  manner  as  for  alloys, 
■with  the  aid  of  a  flux.  The  metals  employed  should  be  pure, 
especially  silver,  as  silver  coin  makes  the  solder  too  hard. 

Solder  for  Silver. — Take  5  parts  pure  silver- not  silver 
coin— 6  parts  brass,  and  2  parts  zinc.  Or.  2  parts  silver,  1  part 
common  pins.  This  is  an  easy  flowing  solder.  Use  a  gas  jet  to 
solder  with. 

Sard  Solder. — Take  2  parts  copper  and  1  part  zinc.  Or, 
equal  parts  of  copper  and  zinc. 

Solder  for  Silver. — Take  19  parts  fine  silver,  1  part  copper, 
and  10  parts  brass. 

Silver  Solder. — Melt  together  .31  parts,  by  weight,  silver 
coin,  and  5  parts  copper  ;  after  cooling  a  little,  drop  into  the 
mixture  4  parts  zinc,  then  heat  again. 

Fine  Silver  Solder.-— 'Sldt  in  a  clean  crucible,  19  parts 
pure  silver,  10  parts  brass,  and  i  i^art  coi:)per;  add  a  small  piece 
of  borax  as  a  flux. 

Solder  for  Cojiper-Same  as  hard  soldering. 

Solder  for  Ttii.— Take  4  parts  pewter,  1  part  tin,  and  1  part 
bismuth.     Use  powdered  rfsin  when  soldering. 

To  give  Bra.'^s  an  Oranffc  Tint.—kn  orange  tint,  in- 
clining to  gold,  is  produced  by  first  polishing  the  I  rass  and  then 
plunging  it  for  a  few  seconds  into  a  neutral  solution  of  crystal- 
lized acetate  of  copper,  care  being  taken  that  the  solution  is'com- 
pletely  destitute  of  all  free  acid,  and  possesses  a  warm  tempera- 
ture 

To  rnhtr  Jirass  Tlolef. — A  beautiful  violet  is  obtained  by 
immersing  the  polished  brass  for  a  single  instant  in  a  solution  of 
chloride  of  antimony,  and  rubbing  it  with  a  stick  covered  with 
cotton.  The  temieruture  of  the  brass  at  the  time  the  operation 
is  in  progress  hivs  a  great  influence  upon  the  beauty  and  delicacy 
of  the  tint;  in  tliis  instance  it  should  be  heated  to  a  degree  so  as 
just  to  be  tolerable  to  the  touch. 

To  give  Jirass  a  Moire  Appeara nee. ~A  moire  appear- 
ance, vastly  superior  to  that  usually  seen,  is  produced  by  boiling 
the  object  in  a  solution  of  sulphate  of  copper.  According  to  the 
proportions  observed  between  the  zinc  and  the  copper  in  the 
composition  of  the  brass,  so  will  the  tints  obtained  vary.  Ui 
many  instunces  it  requires  the  employment  of  a  slight  degree  of 
friction,  with  a  resinous  or  waxy  varnish,  to  bring  out  the  wavy 
appearance  characteristic  of  moire,  which  is  also  singiilarly  en- 
}|i-  need  by  dropping  a  few  iron  nails  into  the  bath. 


IISTIDEIX:. 


AridDipjyinf/,  for  brass,  256. 

Tinning,  for  brass,  257. 
Air-pu!np,  183. 
Alloys  for  bronze,  210. 

For  copper  and  zinc,  210. 

Fusible,  229,  244 

Nickel  and  copper,  227. 

Platinum  and  copper,  220. 

Table  of.  209. 
Aluminnni  solder,  230. 

To  frosl,  2G7. 
Amalgam  of  gold,  231. 
Annealing,  217. 

Antimony,   to   estimate  purity 
of,  2(i7. 

Tests  for,  268. 

Metallic,  269. 
Antimonoid,  233. 
Autiijue  bronze  coloring,  270. 
.\re,is  of  circles,  5 
Argentam,  white,  245. 

Bihhift  Mf'tfil,  211. 

Anti-attrition,  207. 

Lining  bf)xes  with,  212. 
B.dls,  copper,  brass,  cast  iron, 

etc.,  97. 
Barrel,  dimensions  of  a,  36 
Jiath  metal,  2'J6. 
Beams,    strength    of    103,    104, 

105,  113 
Belgian  burnishing  powdrr,2^3. 
Belting,  42. 

Cal(!iilating    horse-power    of, 
46 

Cement  for,  220. 

New,  43. 

Power  of.  42. 

llules  for  finding  length  of  46. 

Tightcnnrs.  45. 

To  measure  a  coil  of  46. 

To  tost  (juality  of,  44. 

Vorticul  double  leather,  44. 


Bell-metal,  227,  213. 

l^ismuth,  269. 

Bismuth,  to  separate,  fro:u  1  a  1, 

269. 
Black  coating  for  metals,  266. 
Black  enamels,  276. 
JJlanched  copper,  250. 
Blue  enamels,  276. 
Boilers,  197. 

Bursting  pressure,  203. 
Consumption  of  fuel,  202. 
Draught    197. 
Fire  and  flue  surface,  20X 
Flues,  198. 

Guarding   against  "incrusta- 
tion, 214,  234. 
lloatiug  surface,  199,  201 
Steam  room,  201. 
Stay  bolts    204. 
Tubes,  weight  of,  90 
Booth's  grease  for  11.  R    axles, 

255. 
Borax,  substitute  for.  211. 
Brass,  for  buttons,  225. 
Cleaning   211. 
Dark,  for  castings,  225. 
Deep  yellow  malleable,  225. 
For  gilding,  225. 
For  turning,  226. 
For  wire   226. 
Lacfjuer  for,  265. 
Liglit  yellow,  225,  242. 
Olive  bronze,  dp  for,  255. 
Poli.shing,  211,  218. 
lied,  225,  242. 
Solution  to  |)re])ar(^  270. 
Solder  for  brazing,  229. 
Tinning   255. 
'i'liat  will  exjiand,  226. 
To  color,  violet,  279. 
To  give,  a  moirti  iii)pearance, 

279. 
To  give,  an  oriingo  tint,  279. 


INDEX. 


281 


Brass,    to   harden   and   soften, 
22G. 

Weiglit  of,  94,  9G. 

Work,  to  lacquer,  264. 

To  prepare,  for  dipping,  257. 
Breast-wheels,  162. 
Bricks,  table  of,  28. 

Ked  wash  for,  261. 
Bricklayers'  work,  27. 
Bridges,  108. 
Bright  polish,  251. 
Britannia  metal,  24*^,  256. 

Hardening  for,  243. 
Bronze,  255. 

Antique,  240. 

Alloys  for,  210. 

Black,  269,  272. 

Brown,  for  medals,  271. 

Chinese,  271. 

Dip  for  brass,  255. 

Fine  green,  238. 

Fontainemoreau's,  228 

For  brass,  239. 

For  cannon,  244. 

For  copi^er,  240. 

For  gun-barrels.  255. 

For  iron  castings,  241. 

For  medals,  244. 

French,  240. 

Green,  for  busts,  239. 

Liquids  for  tin,  240. 

Metal,  243. 

Moire.  210. 

Paint  for  copper  vessels,  25"). 

Phosphor,  227. 

Powder,  red,  241. 

Statuary,  244. 

Surface,  241. 

To  clean,  227. 
Bronzing  with  bleaching  pow- 
der, 240. 

Brass  black,  271. 

Porcelain,    stone-ware,     etc. , 
273. 

Surface,  241. 

With  crocus,  273. 

Wood,  272. 
Browning  for  gun-barrels,  273. 
Brown    tint  for   iron  or  steel, 

213. 
Burden's  spikes  and  horseshoes, 
95. 


Carpenters'  and  fToiners' 
Work,  30. 

Partitions,  staircases,  etc.,  31. 

Joists,  girders,  and  flooring, 
30. 
Calculating  speed,  157. 
Cannon,  bronze   244. 
Capacity  of  cans,  25. 
Case-hardening,   2i)8,  212,   213, 
222,  223. 

Moxon's  method,  223. 

Polished  iron,  222. 

Small  articles,  223. 

With  charcoal,  223. 
Casks,  gauging  of,  36. 

Capacities  of,  37. 

Ullage  of,  38. 
Castings,  to  bronze,  241. 

To  fill  holes  in,  211. 

To  find  the  weight  of,  209. 

Shrinkage  of,  146. 
Cast  iron,  to  bronze,  213. 

Cement,  254. 

To  .scour,  214. 

To  deposit  copper  on,  236. 

To  compute  the  weight  of,  93. 

Weight  of  flat,  97. 

Weight  of  sq.  and  round,  98. 

Pipes,  weight  of,  91. 
Cast  steel,  215. 

Cement  cloth  to  polished  metal, 
221. 

Cast  iron,  254. 

Gutta-percha,  221,  232. 

Gas  retorts,  220. 

Coating  acid  troughs,  222. 

Gutta-percha  and  leather,  222. 

Cracks  in  wood,  221. 

Roman,  264. 

Leather  belting,  220. 

Masons',  261. 

Metal  to  leather,  220. 

Portland,  262. 

Metal  letters  and  glass,  233. 

Steam-pipe  joints,  255. 

Soft  and  hard,  244. 

Water-proof  mastic,  261. 
Centre  of  gyration,  177. 
Centrifugal  force,  178. 
Chains,  weight  and  strength    i, 

101. 
Charcoal,  41. 


282 


INDEX. 


Cliinese  silver,  24j. 

White  copper,  256. 
Circles,    diameters,    circumfer- 
ences, and  areas  of,  5. 
Coarse  stuti"  for  plastering,  2G3. 
Cock  metal,  213. 
Cohesive  power  of  metals,  113. 
Coin  of  United  States,  251. 

Great  Britain,  251. 
Coins,  to  protect,  from  tarnish- 
ing, 271. 
Cold  tinning,  237. 
Columns,  117,  118,  181. 
Common  pewter,  251.  • 
Compression  of  li(piids,  109. 
Commercial  antimony,  2G8. 
Composition  for  welding  steel, 
207,  231. 

For  ornaments,  2G3. 
Concretes,  12C,  2G3. 
Concrete  floors  and  walks,  2G3. 
Cone,  contents  in  gallons  of,  9. 
Cones,  10. 
Copper,  weight  of,  96. 

Blanched,  250. 

Dimensions  of  95. 

To  compute  tlie  weight  of,  93. 

To  separate  from  alloys,  275. 

To  clean,  218 

Reduction  to  powder,  275. 

To  prevent  corrosion  of,  218. 

Feather-shot,  275. 

Alloys  for,  210. 

riatcs.  to  coat  with  brass,  235. 

Separating  silver  from,  25(i. 

Vessels,  to  coat  inside,  235. 

Vessels,  to  tin,  23(1. 
Cu]>ola  furnace,  18. 
Cutting  screws,  159. 
Cylinder,  11. 

Area  of,  187. 

Diameter  of,  182. 

Det'Aituil  Kquivali'iifs  of  a 

gallon,  11. 

D<!trusive  slnnglh,  139. 

])iaiiiiti'rs  of  circli'S,  5. 

Dimensions  of  casks  and   bar- 
rels, 30. 
Of  a  beam,  103. 

Dipping  aoiil,  2")''i. 

J  )ischarge  of  water,  172,  175. 


Distinguishing  iron  from  steel, 

212. 
Drills,  to  temper,  219. 
Dye,  for  wood,  211,  212,  215. 
For  veneers,  216. 

Edge  Tools,  manufacture  of, 

220. 
Elasticity  of  timber,  103. 
Electroplating,  Nagel's  method, 

270. 
Ellipse,  16. 
Enamel,  black,  276. 

Blue,  270. 

Brown,  276. 

Green,  276. 

Olive,  277. 

Orange,  276. 

Purple,  277. 

Red,  276,  277. 

Rose-colored,  277. 
Enamelling  wood,  252. 
Engraving,    mixture  for   steel, 

220. 
Expansion  metal,  228. 
Explanation  of  characters,  1. 

Fasten  i  IK/  J^eather  to  iron, 
233. 

Rubber  to  wood,  232. 
Files,  to  temper,  219. 
Fine  stuff  for  jilastcring,  261. 
Fire-proof  whitewash,  258. 
Flu.'s,  9'.l. 

Fluid  alloy  of  sodium  and  po- 
tassium, 228. 
Fluxes  for  soldering  and  weld- 
ing, 232,  277,  278,  279. 
Flux  for  soldering  brass,  278. 

Britannia  metal,  278. 

Iron  or  steel,  277. 

I'ewter,  277. 

Tin  and  lead,  278. 

Zinc,  278. 
Fly-wheel,  179. 
I'orco,  centrifugal,  178. 
French  polish,  21'.),  250,  251. 
I'rosting  aluminum,  267. 
Furniture,  to  wax,  219. 

To  polish.  218,  219. 

Polish,  2:9. 
Fusibility  of  metals,  181. 


INDEX. 


2h^ 


Fusible  alloys,  229,  244. 
Metal,  228. 
Compounds,  207. 

GflUoil,   decimal    equivalents 

of  a,  11. 
Galvanized   sheet  iron,   weight 

of,  100. 
Gauge  stuflf.  2CA. 
Gearing,  147  to  158. 
German  silver,  243. 
Gilding  with  gold  amalgam,  232. 
Girders,  129. 
Glaziers'  work,  35. 
Glue,  210. 
Gold,  Manheim.  256. 

Coin  of  United  States,  254. 

Coin  of  Great  Britain,  254. 

Solvent  for,  255. 
Gongs  and  cymbals,  22S. 
Gravers,  to  temper,  219. 
(Travity,  specific,  168. 
Grease  for  R  E.  axles,  255. 
Green  enamels,  276. 
Gun,  to  clean,  224. 

Grease  for,  224. 

Metal,  244. 

Barrels,  to  blue,  212. 

Barrelsj  to  ornament,  213. 

Barrels,  browning  for,  273. 
Gutta-percha  cement,  221. 
Gyration,  centre  of,  177. 

Hard  Solder,  256. 
Hardening  for  britannia,  243. 
Heat,  silvering  by,  255. 
Higgins'  stiicco,  2"1. 
Holes  in  castings,  to  fill,  211. 
Hollow    columns,   strength    of, 
117. 
For  mills,  181. 
Horseshoes,  weight  of,  95. 
Hydraulics,  169, 

Compression  of  liquids,  169. 
Difiference  between  true  and 

apparent  level,  170. 
Discharge  of  water  by  hori- 
zontal conduit,  172. 
Liquids  in  motion,  170. 
Diameter  of  pipes,  174. 
Discharge  of  water  by  rectan- 
gular orifices,  175. 


Hydraulics,  motion  of  water  in 
rivers,  175. 
Quantity  of  water  discharged 

in  any  given  time,  173. 
Velocity  of  water,  176. 
Quantity  of  water  discharged 

per  minute  171. 
Weight  of  water,  172. 
Hyperbolic  logarithms,  184. 

IiicrHstatioii  in  boilers,  214, 

233,  234. 
India-rubber,  to  dissolve,  221. 
Instrumental  arithmetic,  17. 

Engines,  power  of,  22. 

Engine  boilers,  power  of,  22. 

Gauge-iioints   for    slide-rule, 
21. 

Gauge-jioints   for    engineers' 
rule,  2'\ 

Mensuration  of  solidity,  21. 

Mensuration  of  surface,  19. 

Numbers    to    divide    on    the 
rule,  18. 

Geometrical  proportion,  19. 

Numbers  to  multiply,  18. 

Numeration,  17. 

Rule  of  three  direct,  18. 

Rule  of  three  inverse,  18. 

Slide  rule,  17. 
Interest  rules,  41. 
Im^jroved  process  of  hardening 

steel,  223. 
Imitation  silver,  243. 

Rosewood,  247. 
Iron,  manufacture  of,  64. 

Balling  up,  74. 

Boiler-plate  iron,  86. 

Blast  refined  iron,  73. 

Cutting  bars  into  lengths,  75, 
81. 

Cutting  and  rolling  rails,  85. 

Form  of  bars,  79. 

Heating  furnace,  75. 

Nail-rod  iron,  87. 

Puddling,  66. 

Refining,  65. 

Reverberatory  furnace,  68. 

Railway  bars,  84. 

Rail  straightening,  86. 

Rolling  the  bloom,  72. 

Rolling  mill,  77. 


284 


INDEX. 


Iron,  rolling  machine,  80. 

Separating  alloyed  matters,  09. 
The  forge  hammer,  71. 
The  lever  squeezer,  71. 
Turning  the  rollers,  77. 
To  soften,  211. 
Bronzing,  213. 
Caseharclening,  208,  212,  213, 

222,  223. 
Cleaning,  215. 
Convert,  into  steel,  215. 
Cover,  with  copper,  236. 
Clean,  for  tinning,  237. 
Tinning,  229,  237. 
Galvanizing,  239. 
Keep,  polished,  216. 
Make  edge-tools  from,  220. 
Remove  rust  from,  213. 
Protect  from  rust,  215. 
Protect  from  oxidization,  213. 
Prevent  decay  of  railings,  215. 

Joavital  Boxes,  lining,  212, 
243. 

Kiilsomlne,  to  prepare,  259. 
Kustitien's  metal  for  tinning,  25. 

Lorqaer,  258,  201,  205,  200. 

Directions  for  making,  257. 
Lateral  pressure,  102. 
Laying  the  color  on  enamelled 

wood,  254. 
Lead  lialls,  weight  of,  97. 

For  cisterns,  217. 

Ores,  217,  218. 

Pipe,  weight  of,  100. 

Pipe,  to  joint,  211. 

Sc^parating  from  copper,  275. 

"Weight  of  a  foot,  90. 

To  compute  the  weight  of,  94. 
Lining  boxes  with  Babbitt  met- 
al, 212. 

Metal  for  journals,  243. 
Licjuids  for  brightening  colors, 
241. 

In  inf)tion,  170. 
Locomotive,  188. 

Miiliinioiif/,  composition  for, 

21H. 

Artificial,  24G. 


Mahogany,  beechwood,  246. 
To  clean,  248. 
To  stain,  247. 
Manheim  gold,  256. 
Marble  workers'  cement,  262. 
Masons'  work,  29. 
Materials,  strength  of,  101-140. 
Melting  point  of  metals,  181. 
Mensuration,  13. 
Circles,  13. 
Cones,  16. 
Cubes,  15. 
Cylinders,  14. 
Ellipses,  10. 
Frustums,  17. 
Polj'gons,  10. 
Rectangles,  15. 
Spheres,  14. 
Scjuare,  15. 
Regular  bodies,  15. 
Triangles,  15. 
Metal,  bell,  227,  243. 
BaV)bitt,  211. 
Bath,  256. 
Bronze,  243. 
Black  coating  for,  266. 
Britannia,  243. 
Babbitt's  anti-attrition,  207. 
Cock,  243. 

Cohesive  power  of,  113. 
Expansion,  228. 
For  gongs  and  cymbals,  228. 
For  telescopes,  244. 
Fusible,  228. 
Fusibility  of,  181. 
For  impressions,  244. 
Gun,  244. 
Hard  white,  213. 
Kustitien's,  for  tinning,  25. 
Lining,  for  journals,  243. 
(Queens,  255. 
Rivet,  244. 
Speculum,  227,  256. 
Silver  colored,  243. 
That  expands  in  cooling,  254. 
Tvpe,  245. 
Metric  system,  205,  200. 
.Mixture  for  silvering,  255. 
Mock  ])latiiiuui,  255. 
Moulding  and  founding,  47. 
Cupola  furnace,  48. 
Deterioration  of  castings,  56. 


INDEX. 


285 


Moulding  and  founding,  effects 

of  hot  blast,  55. 
Effects  of  hot  gases,  60. 
Effects  of  prolonged   fusion, 

59. 
Effects    of    remelting    crude 

iron,  58. 
Effects  of  slow  cooling,  61. 
Green  sand  castings,  50. 
Loam  moiilding,  52. 
Moulding  pulleys,  51. 
Moulding  gearing,  53. 
Open  sand  moulding,  49. 
Precautions,  53. 
Properties  of  cast  iron,  54. 
Kosistance  of  cast  iron,  63. 
To  compute    the   weight    of 

iron,  93 
Tensile  strength  of  cast  iron, 

55. 
To  chill  cast  iron,  62. 
Weight  of  cast  ii'on  pipes,  91. 
Models,  proportion  of,  110 

Niifjel  '.s'  Method  of  Elcc- 

frojjlafing,  270,  272. 
Nail  rod  iron,  87. 
New  plastic  material,  262. 
New  tinning  process,  25. 
Nitric  acid  dips,  to  repair,  257. 
Number  of  nails  in  a  pound,  32. 

Olive    Bronze    Dip    for 

Brass,  255. 
Orange  enamels,  276. 
Ores,  to  estimate  percentage  of, 

212. 
Ormolu  dipping  acid,  256. 
Overshot  wheels,  160. 

Painters'  WorU,  34. 

Pale  tin  lacquer,  266. 

Papering  whitewashed  walls, 
261. 

Patterns,  varnish  for,  236. 

Pavers'  work,  34. 

Percentage  of  iron  in  ores,  212. 
"  "  lead      "         218. 

Petrifying  wood,  235. 

Pewter,  common,  254. 

Philosophical  instruments,  lac- 
quer for,  267. 


Phosphor  bronze,  227. 
Picks,  to  temper,  218,  219. 

"     bath  for  hardening,  219. 
Pinchbeck,  244 
Pipes,  weight  of  various,  10. 

"       cast  iron,  weight  of,  91. 
Pistons,  185. 
Planting,  49. 

Plastering,  fine  stuff  for,  261. 
"  coarse     "        263. 

Plasterers'  work,  34. 
Plaster  casts,  to  bronze,  272. 
Plate  boiling  powder,  275. 
Platinum,  267,  268. 

To  purify,  268. 
Platinum,  mock,  235. 
Platinum    and    copper    alloya, 

226. 
Ploughing,  39. 
Plumbers'  work,  36. 
Polishing  brass  ornaments,  248. 

French,  249,  250,  251. 

Furniture,  248,  249. 

Turners'  work,  252. 

French  method,  247. 

Paste,  250. 

Varnish,  247. 

Strong,  253. 
Polygons,  16. 
Portland  cement,  262. 
Powder,  burnishing,  273. 
Prepared   spirits  for  finishing 

polish,  251. 
Pressure  of  steam,  191. 
Preserving'  wood,  235. 
Pumice-stone    for    enamelling, 
253. 

Qualitjf  of  Tin  Plate,  24. 

Quantity  of   copper  in  a  com- 

jwund,  275. 
Queen's  metal,  255. 
Quick  dipping  acid,  256. 

Railway  Pars,  84. 

Spikes,  94. 
Rectangles,  15. 
lied  enamels,  276. 
E,e<l  wash  for  bricks,  261. 
Regular  bodies,  15. 
Restoring  burnt  steel,  211,  212, 
219, 


286 


INDEX. 


Revolving  disk,  116. 

Rivet  metal,  2H. 

Rolling  mill,  64,  81. 

Romiin  cpment,  264. 

Ropes,  strength  and  weight  of, 

101. 
Rosewood,  to  imitate,  247. 
Round  rolled  iron,  weight  of, 

91. 
Rust,  to  protect  from,  224. 

To  remove,  213,  224,  22">. 

To  protect  steel  from,  271. 

Screw  Ciitfim/,  159. 
Scale  in  boilers,  214,  234. 
Seals  and  stamps,  216. 
Separating  silver  from  copper, 
256. 

Tin  from  copper,  274. 

Lead  from  copper,  275. 
Sheet  iron,  weight  of,  158. 

Weight  of,  galvanized,  100. 
Ship  spikes,  1)4. 
Shrinkage  of  castings,  146. 
Silverware,  to  protect,  from  tar- 
nishing, 274. 
Silver,  German,  243. 

Coin  of  U.  S.,  54. 

"     "  Great  Britain,  254. 

Colored  metal,  243. 

Cleaning,  274. 

Imitation,  213.    ' 
Silvering  by  heat,  255. 
Slates,  table  of  domestic,  31. 

Imported,  33. 
Slaters'  work,  32. 
Solder,  tinman's,  254. 

Gray  cast  iron,  22'J. 

To  make,  27'J. 

Soft,  278. 

For  silver,  279. 
"    gold,  278. 
"    copper.  279. 
•'    tin,  271). 

Hard.  256,  278,  279. 
Soldering  fluid.  2'i7   277. 

For  soft  sf)ldor  277. 

For  iron,  cojuxir,  and   brass, 
230. 

Flux  fnr,  277. 

For  aluminum,  230. 

Noutrul,  277. 


Solid  columns,  115. 
Solvent  for  gold.  255. 
Spanish  tutania,  244. 
Specific  gravity,  16  <. 
Speculum  metal,  227,  25ft. 
Spcmgv  platinum,  269. 
Stain,  "black,  246,  247. 

French  i^olish,  251. 

Mahogany,  246,  247. 
Standard  French  polish,  250. 
Statuary  bronze,  244. 
Steel,  annealing,  217. 

Blueing,  216,  219. 

Composition  for  welding,  207. 

Cast   to  make,  216. 

Hardening,  223. 

Remove  scale  from,  216. 

Restoring  burnt,  211,  212,  219. 

Softening,  211. 

Toughening.  211. 

Made  from  iron  scraps,  215. 

Shear,  to  make,  216. 

Tempering,  219. 

"  springs.  216. 

Straightening  hardened.  217. 

To  protect  from  rust,  225,  271. 

Weight  of,  96. 

Writing  on,  220. 
Steam  and  steam-engine,  182. 

Areas  of  cylinders,  187. 

Computing  lap  of  valves,  193, 

lead        "        194. 

"         stroke    "         195. 

Circumference      of     driving 
wheels,  184. 

Cylinder,  condenser,  and  air- 
pump,  183. 

Diameters  of  cylinders,  182. 

Dimensions  of  a,  locomotive, 
188. 

Hyperbolic  logarithms,  184. 

Nniiiiiial  power  of,  182. 

Bower  of  steaiu,  196. 

I'ressure  of  steam,  191. 

Revolution  of  drivers,  190. 

Slide  valves,  192. 

Steaui    pipe    joints,    cement 
for,  255. 

Travel  of  valves,  18f>. 

Throw  of  eccentrics,  186. 

Velocity  of  ])istons,  1H5. 

Water  for  injections,  183. 


IXDEX. 


287 


Strength  of  materials,  101. 

Bar  of  iron,  108. 

Beams,  lOG,  103,  113.  11^. 

Bridges,     floors,    and    roofs, 
lOJ. 

Cast  and  malleable  iron,  113. 

Cast  iron  beams,  105. 
"      "     girders,  135. 

Concretes,  cements,  etc.,  126. 

Cohesive  power  of  bars,  113. 

Copper,  12i. 

Detrusive  strength,  139. 

Dimensions  of  bars,  131. 

Floors,    beams,   girders,    itc, 
133. 

Girders,  beams,  &c.,  129. 

Hollow  columns,  117. 

Lateral  pressure,  102. 

Materials  of  construction,  102. 

Models,  110. 

Resistance  of  torsion,  108. 
"   bodies,  105. 

Kectangiilar  beams,  104 

Eound  columns,  118. 

Shafts  and  gudgeons,  140. 

Solid  columns,  115. 

Transverse,  124,  129. 

Tensile,  119,  121,  123. 

Torsional,  107,  137. 
Stucco,  Higgins',  261. 

For  inside  walls,  262. 
Square  rolled  iron,  weight   of, 

90. 
Square  vessel,  contents  of,  9. 
Substitute  for  borax,  211. 

Tempering,  208,  219. 

By  thermometer,  208. 

Drills,  219. 

Gravers,  219. 

liles,  219. 
Tempering  liquids,  211. 

Spiral  springs,  216. 

Steel.  219. 
Tensile  strength,    55,    119,  121, 

123. 
Throw  of  eccentrics,  186. 
Timber,  141. 

Felling,  142. 

Impregnation  of,  144. 

Seasoning    and     preserving, 
142. 


Timber,  weight  and  strength  of, 

145. 
Tin,   to  sepai'ate  from  copjjer, 

274. 
Tinman's  solder,  254. 
Tinning,  25. 
Brass,  2j5. 
Copper  tubes,  238. 
vessels,  230. 
"       brass,  and  iron,  238. 
Cold,  237. 

Iron  for  soldering,  229. 
"    pots,  237. 
"    without  heat,  237. 
Kustitien's  metal  for,  25. 
Moist  way,  237. 
Tin  plate,  sizes  and  weight  of, 
12. 
Crystallized,  24. 
Lacquer  for,  265,  266. 
Manufacture  of,  22,  23. 
Quality  of,  24. 
To  find  the  weight  of  any  cast- 
ing, 209. 
To  joint  lead  jiiiies,  211. 
Tombac,  red,  226,  243. 

White,  227. 
Torsional  strength,  107. 
Transverse  strength,  127,  129. 
Travel  of  valves,  186. 
Treasury  Dept.  whitewash   2j8. 
Triangles,  15. 
Turbines,  164. 

Turner's  work,  polish  for,  252. 
Tutania,  229,  244, 
Tutenag,  228.  245. 
Type  metal,  215. 

UlJar/e  of  Casks,  37. 

Undershot  wheels,  162. 
Use   of    petroleum   in   turning 
metals,  228. 

Valves,  Slide,  186,  192,  193, 

194,  195. 
Valuable  intoi-est  rules,  41. 
Varnish,  207,  256. 
Varnish  for  patterns,  256. 
Velocity  of  water,  176. 
Veneers,  to  dve,  245. 

Black,  245. ' 

Rose  color,  246. 


fi88 


INDEX. 


Veneers,  to  silver  gray,  246. 

Yellow,  24(). 
Vessel,   contents   in  gallons   of 

any,  9. 
Vinegar  bronze  for  brass,  257. 

Walls,  to  irliiteu'ush,  2G0. 

To  kalsomine,  259. 
Walnut,  to  give  a  dark  surface, 

252. 
"Water,  1C6. 

Weight  of,  11. 

Power  of,  161. 

Velocity  of,  176. 
Water- proof  polish,  251. 
Water-wheels,  160. 

Breast,  162. 

Overshot,  160. 

Power  of,  161. 

Power  of  a  stream,  161. 

Eemarks  on,  163.   . 

Turbines,  16-t. 

Undershot,  162. 
Weight  of  boiler  tubes,  99. 

Brass,  96. 

Brass  an<l  lead  balls,  97. 

Cast  iron.  Hat.  97. 

"     round,  93. 
"       "     pipes,  91. 

Copper,  96. 

Lead,  96. 

"     pipe,  100. 

Pipes  of  various  metals,  10. 

Ropes  and  chains,  101. 

Round  rolled  iron,  91. 

Sheet  iron,  158. 

«'         "     galvani/.id,  100. 

Bteel,  96. 


Weight  of  square  rolled  iron,  90. 

Tm-plate,  12. 

Wuter,  11. 

Wood,  40. 
Welding  compositions,  230. 

For  cast  steel,  207,  231. 

For  steel   231. 

Fluxes  for  welding,  232.  277, 
278,  279. 
Welding  powder,  231. 
Wells  and  cisterns,  29. 
Well  digging,  29. 
Wheel  gearing,  147,  159 
Wliitewash,  258,  259,  260,  261. 
White  argeiitam,  245. 

Metal,  243. 
Wire  rope,  123. 

Wonders    of    American    Conti- 
nent, 41. 
Wood,  bronzing,  272. 

Dyeing.  241,  242,  245. 

Enamelling,  252,  254. 

Kyanizing,  234. 

Petrifying.  235. 

Preserving,  235. 

"  under  water,  235, 

Prevent  decay  of,  233. 
"      splitting,  234. 

Staining,  245. 

black,  246. 
"        mahogany,  246. 

Weight  of  a  cord,  40. 

Yelhur    Dipitinq    Metal., 

256. 

Zhtr,  rnrifieation  of,  224. 
Zinc  whiti;wiush,  261. 


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